Featured Article – What Are UVC Wands and Do They Work?

In the fight against COVID-19 (and as made famous by U.S. President Trump’s comments about UV light) UVC wands may kill viruses and pathogens, but are they really a safe or effective tool in the fight against COVID-19?

What Are UVC Wands?

UVC light is a kind of ultraviolet electromagnetic light/radiation that has short wavelengths (between 200 and 280 nanometers/nm).  This kind of light can alter the DNA of the Ribonucleic Acid (RNA) of organic cells. Essentially, this alteration by UVC can stop the organic cells from reproducing.  The use of UVC light in cleaning has, therefore, been to kill germs in water, air, food, or on surfaces.

UVC wands, as the name suggests, are hand-held directional UVC lamps in a wand shape.

COVID-19 and Surfaces

COVID-19 is known to be able to live on surfaces, although the time varies with the type of surface and between the different studies and estimates.  For example, as shown in the results in the New England Journal of Medicine, COVID-19 can live longest in plastic (up to 72 hours), whereas it can live on stainless steel for up to 48 hours, just 24 hours on cardboard, and only 4 hours on copper.

The fact that COVID-19 is a virus that can live on surfaces means that it could, therefore, be cleaned from that surface using cleaning products or, for example, a UVC wand.

Do They Work?

The short answer is yes if they are not underpowered or fake (there are fakes for sale online), they can be effective at disinfecting surfaces. It should be noted, however, that the distance and duration that a wand is held from an infected surface are both important factors in how effective a cleaning job can be.  Generally speaking, smooth surfaces such as glass are easier to disinfect than wood, cloth, or other textured surfaces where virus particles could settle. 

Wher They Are Being Sold

The pandemic has led to a surge in demand for UVC wands. This has generated greater sales for existing, trusted manufacturers, and has created opportunities for other manufacturers, but has also led to an online market for perhaps less effective and cheaper devices.

Health Risks To Humans

UVC rays occur naturally in the light from the sun but are normally filtered out when they react with ozone high in the earth’s atmosphere.  Devices such as arc welding torches, mercury lamps, and UVC wands/sanitizing bulbs, however, pose a health risk to exposed human skin (and eyes). Unlike UVA and UVB light that can cause sunburn and skin damage if a person sits unprotected in the sun for hours, UVC is much more intense and can burn a person’s skin within seconds.

Although UVC helps to protect humans by killing viruses and pathogens that may have settled on a surface, it can cause serious damage to human skin e.g. as a cause of skin cancer. The degree of damage depends upon factors such as the UVC wavelength, the dose, and the duration of radiation exposure. Those using UVC wands without being aware of the risks (e.g. not covering skin) and using the wands for prolonged periods may not be aware of the damage caused until several days after exposure.


Although UV rays do not penetrate deeply into the body, they do affect the outer layers such as the skin, and exposed, delicate areas such as the eyes (basal and squamous cells).  Just as it is known that the use of use UV tanning beds/booths, especially when a person is under 30, can increase the risk of skin cancer e.g. melanoma and squamous and basal cell skin cancers, too much exposure to UVC light also brings a cancer risk.

The International Agency for Research on Cancer (IARC), part of the World Health Organization (WHO), for example, is very clear that “UV radiation (including UVA, UVB, and UVC) is carcinogenic to humans.”

The kinds of cancers that can be caused by UVC light, and possibly by incorrect use of UVC wands include basal cell and squamous cell cancers, melanoma (of the skin and the eye), and  Merkel cell carcinoma which is a less common type of skin cancer.

Protection From UVC

Protection from exposure to UVC (e.g. when using a UVC wand as part of a job) involves:

– Using the device according to the manufacturer’s instructions.

– Wearing protective clothing and using UV shields and filters.

Looking Ahead

In terms of keeping surfaces in workplaces, hubs, and accommodation (e.g. hotels) clean, UV light has long been used as a tool to fight the spread of germs.  The pandemic, and the lack of any vaccine or effective, widely available treatments to date have made people consider using tools such as UVC wands.  This has created opportunities for businesses manufacturing and selling these devices but has also created opportunities for fraudsters to sell fake/ineffective versions of these devices online.  It is important to remember that UVC wands from trusted sources can be an effective tool for cleaning surfaces and killing viruses that may have settled on those surfaces, such as COVID-19.  It should also be remembered that unless safety procedures and manufacturer’s instructions are followed, and unless protective clothing and items are worn/used, UVC light devices can pose a serious health risk. Robotic applications look likely to become more widespread.

Lockdown Love Scams

Details emerged this week of a scam whereby a man claiming to be on a top-secret military mission contacted a lady on a dating site and encouraged her to switch to an encrypted message service in order to steal money and personal details.


In this particular scam, reported by the BBC, the victim appears to have been targeted and hooked via a military connection (a partner in the military). After a charm offensive via messaging on a dating app, the scammer, who used a fake photo, manipulated the victim into switching their conversations to a messaging app in order to avoid scrutiny.

With any scams, the motivation is always to steal money, or steal personal details (in order to get more money) or both.

Military – A Common Theme

Scammers often claim to be in the military because it instils trust. The ‘secret mission’ aspect creates excitement, intrigue, and gives the scammer a get-out clause plus protects their real identity and the scam as they can hide behind this in order to avoid answering questions.

Yahoo Boys

In countries such as Nigeria, for example, where there is poverty, political corruption and a large number of internet service providers, scammers (often young students) calling themselves ‘Yahoo Boys’ have been operating romance scams for many years, sharing data on (less tech-savvy, mainly female) soft targets in other, richer countries in order to steal money.  Phishing on dating or social network sites is a common scamming method.

More lucrative scams for Yahoo Boys involve getting an insider job at a bank to scam money directly and exploiting informal networks based around banks, security agencies, other fraudsters, and family members.

Getting Rich

Some Yahoo boys have achieved notoriety for the fortunes they have made. For example,  names such as Ray Hushpuppi, Ismaila Mompha, and Olalekan Ponle/“Woodberry” are names that can be found online linked to fortunes made as ‘Yahoo Boys’.

How To Avoid Romance Scams

Measures that can be taken to avoid becoming the victim of a romance scam include:

– Telling a trusted friend about what the person has contacted you has said about themselves and their intentions. This provide a valuable way to gain another perspective and can be a first (important) ‘reality check’.

– Only use trusted dating websites.

– Do not share real personal details or personal contact details.

– Never send or receive money to and from someone who has contacted you online.

– Trust your instincts.

What Does This Mean For Your Business?

Scammers operating through businesses such as dating platforms are a risk to those businesses and the victims themselves and although platforms can make it harder for scammers to operate, scammers can be very resourceful and bold.

Identity fraud and romance scams are all too common and a large part of stopping them is education about the existence of these scams, how the scammers operate and how to avoid being targeted.  Unfortunately, some scammers are particularly adept at spotting and exploiting vulnerability.

For businesses wanting to know how to avoid being scammed, the Met’s tips can be useful.  These are to be sceptical, to know your business inside out, to know customers and suppliers, identify areas where your business is vulnerable to fraud, develop a strategy and talk about fraud, take extra care against cyberattacks, understand your finances, secure and protect your property, develop an action plan, and be sure to report any frauds that do occur.

Can Wearable Devices Spot Early Symptoms of COVID?

As wearable devices such as fitness wristbands and watches track signs such as body temperature, could they be used to help detect the early signs of COVID-19 infection and thereby help public health responses?


There are now many ‘wearables’ (health and fitness related devices) on the market such as Fitbits (and other fitness-tracking wristbands), Apple and Garmin Watches, and even ‘smart’ items of clothing. The idea that some researchers have been testing is that wearable devices could act as a kind of early symptom-spotting device for the wearer for conditions like COVID or flu.


For example, back in January, before the pandemic’s huge spread, research published in the Lancet detailed how researchers had noted that when people are fighting an illness such as influenza, their heart rates are faster, their sleep routines are different to normal, and they tend to spend more time sitting/lying down.  With this in mind, the researchers used fitness data from more than 47,000 Fitbit users across five U.S. states to test whether a Fitbit device could be used to improve influenza predictions compared to traditional flu surveillance methods (which can take weeks).  The researchers found that using the Fitbit data could enhance flu surveillance and consequently improve public health responses.

Wearables Detecting Symptoms

It does appear to be possible, therefore, that wearable devices could detect some symptoms/signs of COVID-19 infection.  For example, wearable temperature patches that send data to smart devices could help to record temperature and sweat rate could be measured by sensors that detect compounds in sweat.


Much of the research for rapid pathogen detection, however, is heading in the direction of trying to develop miniature ‘lab-on-a-chip’ testing.  One example is research focusing on the development of an ion-sensitive field-effect transistor (ISFET) that can detect the presence of an RNA virus i.e. a virus with RNA (ribonucleic acid) as its genetic material.  Such viruses include the common cold, influenza, SARS, COVID-19, Dengue Virus, and Hepatitis C.

What Does This Mean For Your Business?

Wearable technology is growing in popularity and health/exercise-related wearables such as bracelets continue to provide helpful insights that can help with healthy living and, therefore, help build healthier immune systems or reduce the chances of users suffering badly from diseases if they do catch them.  For example, COVID-19 appears more likely to severely affect those who are overweight.  Enhancing wearables with more medical diagnostics is an exciting prospect that could provide opportunities for specialised businesses. Research, however, is still in the relatively early stages and there are several big challenges to overcome including creating accurate diagnostic (miniature) technology, and privacy and security challenges in the sharing of fitness/medical data from wearables.

Record Broadband Compensation Pay-Outs

Ofcom’s annual report shows that a record-breaking £20.7m in compensation was paid to broadband customers under the new automatic compensation scheme in the last six months of 2019.

The Automatic Compensation Scheme

Back in November 2017, Ofcom announced that broadband and landline customers would, under a planned new scheme (in two years) automatically be able to get compensation from their providers when things go wrong without the need for a claim.  At the time, an £8-per-day compensation voluntary agreement was reached between Openreach and five of the UK’s internet service providers – BT, Sky, TalkTalk, Virgin Media, and Zen Internet.  Others such as PlusNet joined later.  The agreement was prompted by a review and intervention in the broadband market by regulator Ofcom, which introduced a voluntary Code of Practice.

The compensation scheme formally started in April 2019 against a backdrop of 7.2 million cases of broadband or landline customers suffering delayed repairs, installations or missed appointments per year and before the announcement of the scheme only 1 in 7 customers received compensation, which was partly due to having to go through a claim process.

Jumped From £8m to £20.7m

The Ofcom report shows that in last 6 months of 2019, £20.7m in compensation was paid to disgruntled broadband customers compared to the £8m that was paid to customers in the first six months of 2019 before the automatic compensation scheme was introduced.

The £20.7 in compensation pay-outs are reported to include £9.7m for delayed repairs following loss of service, 1.6m for missed appointments and £9.5m for the delayed provision of new services.

Satisfaction Despite Complaints

Curiously, even though there have been record-breaking compensation pay-outs, the Ofcom report shows that 85 per cent of customers were actually satisfied with their broadband service and 90 per cent of mobile customers reported being happy with their phone service.

PlusNet Top – TalkTalk Bottom

The Ofcom report shows PlusNet customers as being the most satisfied with their broadband and TalkTalk users the least satisfied with their broadband services.

What Does This Mean For Your Business?

For businesses, a fast and reliable broadband connection is vital to operate and compete effectively in today’s marketplace. Problems with broadband services can be very costly and frustrating for businesses, and many businesses felt that they shouldn’t have to fight for compensation on top of the problems caused by poor broadband services and that old levels of compensation were too low, and didn’t come close to reflecting the harm caused. Automatic compensation is, therefore, helpful, and the numbers appear to show that many more businesses are at least getting something under the new scheme, helped by the fact that the barrier of a claims process has been removed.  Many businesses may still think, however, that the amounts on offer are unlikely to cover the disruption and problems caused after several days of broadband problems.

The automatic compensation scheme is good news for small businesses because one-third of small and medium-sized enterprises (SMEs) choose residential landline and broadband services, and around half (49%) of SMEs don’t know if they’re entitled to compensation when service falls short (Ofcom figures).

It is also reassuring to know that the main providers are on board with the scheme and that Ofcom plans to keep monitoring its implementation, review it after one year, and step in if it’s not working well enough for customers. The monitoring, however, may lead service providers to feel that they are paying too much under the new scheme and the danger is that this could be reflected in higher broadband charges.

Tech Tip – One-Click Fix For Accessibility

If you are using Word (or any Office app) in Windows 10, there is a one-click way to make sure that your messages and documents can be read by people of all abilities.  Here’s how:

– With your chosen document open click on ‘Review’ (top menu).

– Click on ‘Check Accessibility’ (top left).

– Follow any correction instructions in the right-hand panel.

Featured Article – Back to Work!

For those whose workplace would normally be the office, going ‘back to work’ after remote working during the pandemic has its own challenges, so here is a brief reminder and checklist for moving back to the office to work.

New Rules To Protect Physical and Financial Health

The return to office requires new rules and what some call pandemic management protocols (PMPs) that can help maintain a safe office environment for all and avoid the kind of critical risks that could lead to regulatory action, lawsuits, and could threaten the financial (as well as the physical) health aspects of a business. For the time being, and as suggested by Forrester Research, weaknesses, threats and risks that businesses need to consider in their planning include:

– Changes in the behaviours and attitudes of their customers and staff.

– Changes in supply chains and customers – some of those businesses may not exist or may cut back on or change their orders and/or new suppliers may need to be sourced or contacts may have changed.

– The risks posed by an economic recession.

– The risks of a second wave and the need to re-organise in the event of the effects of local lockdowns on regional offices/branches of the business.

– The increase in costs or re-opening offices, re-organising the workplace and resources, increased cleaning, the costs, and operation of any screening equipment e.g. temperature screening, and the costs of providing hand sanitiser, masks plus safety labelling and signage.

Other potential legal risks to consider include:

– Making employees return before they are ready

– Discriminating between employees e.g. on age, gender, or health grounds.

– Violating privacy and security rights of employees and customers e.g. as more contact details are collected or failing to address the risk of increased cyber-attacks as cybercriminals may have taken advantage of remote working and any return to work confusion.


One of the first issues that springs to mind is the organisation and the cleanliness of the physical office environment. After an initial deep clean e.g. by professional deep cleaning (fogging) specialists, there may need to be subsequent deep cleaning if any staff test positive.  New COVID-safe cleaning regimes need to be established (particularly targeting contact points in the building) and hand sanitiser needs to be provided at key points in the office. Assessments that may be needed before a workplace return could include:

– Conducting new Health and Safety risk assessments, taking the COVID-19 risk into account.

– Checking whether ‘clocking in’ can be done online or by another non-contact, safe method.

– Whether (and how) physical meeting rooms can be used and the arrangements regarding lifts.

-The toilets are likely to need more rigorous and frequent cleaning, with the addition of more sanitizer and labelling.

Screens, Notices, Labelling and Directions

Any screens, new layouts, and directions for movement flow (customers and staff) need to be installed, made clear, tested, and labelled.  Safety labelling needs to posted and maintained around the work premises with responsibility allocated to relevant staff members.

Staffing and Policies

Policies that need to be considered/changed and communicated for the return to work include time arrivals and lateness, working at home and mobile working.

For many businesses, it may be a case of organising new rotas for a staged recovery which could mean staggered work times for staff in order to maintain social distancing. Staff will also need to be told how to report Covid-19 related issues.

Other assessments and checks will need to include:

– Getting up-to-date details for staff, and their next of kin.

– Assessing which employees are high risk, who can come back to work in what role effectively band safely, and how employees can reach their work as safely as possible.

– Discussing, clarifying, and communicating Furlough/return from Furlough arrangements.


The pandemic has brought business continuity and disaster recovery planning into sharp focus.  These plans should be reviewed and updated in relation to the move back to the workplace.


With staff returning, there needs to be enough of the right equipment in the workplace and that equipment needs to be operated safely. Considerations could be:

– Whether all work devices and other equipment (e.g. headsets, office chairs etc) have been returned and whether repairs/replacements are needed.

– Whether company vehicles have been returned and checked and whether repairs are needed.


The office telephone system will need to be switched back over at the right time for the right numbers, with divert and voicemail being changed appropriately.  This will also need to be tested to ensure it is working correctly.


The water, electricity and gas will need to be turned back on at the right time and checks will need to be made to ensure that any water testing procedures (e.g. for Legionnaires’ Disease) and any pest control monitoring/testing are re-instated.

Connections and Network

The broadband and Wi-Fi connections will need to be working and network security checks made e.g. virus checking of devices that have been returned and checking that any temporary remote access methods that were enabled have been closed.

Website and Social Media

Any announcements via the website (blog) or social media concerning any changes to services, and restrictions or requirements (e.g. masks if customers visit business premises) will need to written and published plus any changes to opening hours made to the website.

The addition of any website or social media-based services should also be published.

Collaborative Working, Meeting and Communication Arrangements

Whereas work and projects may have been carried out collaboratively online, and meetings held e.g. using video conferencing, any changes made to these arrangements need to be clearly communicated to relevant staff.

Physical Security

Any physical security arrangements that were needed prior to lockdown and remote working need to be reinstated, tested and relevant details and responsibilities communicated to the right people.  For example, this could include testing the CCTV and access control system, reminding relevant people of alarm/barrier/door codes and testing alarm systems.

Looking Ahead

Whether a staggered and staged return in some businesses or a complete return (e.g. for smaller businesses), the business environment has been changed by the pandemic and the work environment must be changed to take account of this and to ensure safety and business continuity. Although the time may seem right for an operational business recovery, the risks of possible outbreaks, local lockdowns or even a second wave in the winter months remain real possibilities that businesses will need to make real, workable plans for moving forward.

Toyota To Upload Your Data To Amazon

Toyota will use Amazon’s (AWS) cloud services for a Mobility Services Platform that will upload data from Toyota cars globally that could be used for monetised services.

Data Gathering From Fleet

Toyota’s platform in Amazon’s cloud will gather data from the Data Communication Module (DCM) in each car in Toyota’s global fleet which could be used to help Toyota’s vehicle design and development, but more crucially for services such as ride and car sharing, full-service lease, or behaviour-based (custom) insurance and proactive maintenance notifications.  The use of Amazon’s cloud tech and professional services by Toyota and the sharing of data is intended to help the move towards CASE (Connected, Autonomous/Automated, Shared and Electric) mobility technologies.


Shigeki Tomoyama, Chief Information & Security Officer and Chief Production Officer at Toyota Motor Corporation said that in expanding Toyota’s relationship with AWS, “Connectivity drives all of the processes of development, production, sales and service in the automotive business. Expanding our agreement with AWS to strengthen our vehicle data platform will be a major advantage for CASE activities within Toyota.”

Leveraging Data and AWS Services

Andy Jassy, CEO of AWS, said that “Toyota is leveraging the unmatched breadth and depth of AWS services to transform how it develops and manages new mobility services across its entire ecosystem of connected vehicles around the world,” and “By running on AWS, with its high performance, functionality, and security, Toyota is able to innovate quickly across its enterprise and continue to lead the automotive industry in delivering the quality of experiences that customers expect.”

AWS and Other Automotive Companies

AWS is already working with other big car manufacturers such as Germany’s Volkswagen AG on its cloud-based software and data portal and has worked with transportation providers such as Uber and Avis, and self-driving heavy truck company Embark.

What Does This Mean For Your Business?

The vehicle market is changing and the ability to gather data about how vehicles are used looks likely to be another key way in which vehicle manufacturers can compete and to create and target more monetised and value-adding services.  It will also create new opportunities for associated industries e.g. the ability to create customised insurance for drivers. For drivers, there may be more cause for concern in terms of data protection and privacy if their identity is linked with car data e.g. for custom insurance, as theft of this data could have negative implications.

AI-Faked Photos and Videos Concerns

Social media analytics company Graphika has reported identifying images of faces for social media profiles that appear to have been faked using machine learning for the purpose of China-based anti-U.S. government campaigns.

Graphika Detects

Graphika, which advertises a “Disinformation and Cyber Security” service (whereby it can detect strategic influence on campaigns) has reported detecting AI-generated fake profile pictures and videos that were being used to attack American policy and the administration of U.S. President Donald Trump in June, at a time when the rhetoric between the United States and China had escalated.

The Graphika website has posted a 34-page file online detailing the findings of what it is calling the “Spamouflage” campaign.  See: https://public-assets.graphika.com/reports/graphika_report_spamouflage_goes_to_america.pdf

Spamouflage Dragon

The China-based network that, according to Graphika, has been making and spreading the anti-U.S. propaganda material via social media has been dubbed “Spamouflage Dragon”.  Graphika says that Spamouflage Dragon’s political disinformation campaigns started in 2019, focusing on attacking the Hong Kong protesters and exiled Chinese billionaire Guo Wengui (a critic of the Chinese Communist Party), and more recently focused on the U.S and the Trump administration.

Two Differences This Time

The two big differences in Spamouflage Dragon’s anti-U.S. campaign compared to its anti-Hong Kong protester campaign appear to be:

1. The use of English-language content videos, many of which appear to have been made in less than 36 hours.

2. The use of AI-generated profile pictures that appear to have been made by using Generative Adversarial Networks (GAN).  This is a class of machine-learning frameworks that allows computers to generate synthetic photographs of people.

Faked Profile Photos and Videos

Graphika reports that Spamouflage Dragon’s U.S. propaganda attacks have taken the form of:

– AI-generated photos used to create fake followers on Twitter and YouTube.  The photos, which were made up by GAN from a multitude of images that have been taken from stolen profile photos from different social media networks were recognisable as fake because they all had the same blurred-out background, asymmetries where there should be symmetries, and the eyes of the subjects were all looking straight ahead.

– Videos made in English, and targeting the United States, especially its foreign policy, its handling of the coronavirus outbreak, its racial inequalities, and its moves against TikTok.  The videos were easily identified as fake due to being clumsily made with language errors and automated voice-overs.

What Does This Mean For Your Business?

With a presidential election just around the corner in the U.S. and with escalating tensions between the super-power nations, the fact that these videos, AI-generated photos and their fake accounts can be so quickly and easily produced is a cause for concern in terms of their potential for political influence and interference.

For businesses, the use of this kind of technology could be a cause for concern if used as part of a fraud or social engineering attack. Criminals using AI-generated fake voices, photos and videos to gain authorisation or to obtain sensitive data is a growing threat, particularly for larger enterprises.

Ritz Roasted

Some diners with bookings at the Ritz Hotel were reportedly targeted by phone scammers who posed as hotel staff to steal credit card details.

What Happened?

The ID spoofing attack involved the fraudsters pretending to be hotel staff, phoning people who already had a dining reservation at the Ritz and asking them to confirm their credit card details, or saying that their card had been declined and asking for a second bank card.

It has been reported that the telephone calls from the scammers were made to appear to come from the Ritz telephone number and that the scammers knew the correct booking details of diners.

It remains unknown exactly how the scammers obtained the details, and the incident and possible data breach was reported by the Ritz to the Information Commissioner’s Office (ICO).

Tried To Spend At Argos

It has been reported that the scammers used the details stolen from a Ritz diner’s card to attempt to buy over £1,000 of goods at the catalogue retailer Argos. When the victim’s bank noticed the transaction, the scammers then phoned the victim, pretending to be the bank, asking for a security code that had been sent to her mobile phone that would enable the cancellation of the Argos transaction.  In fact, the code would have enabled the authorisation of the transaction and the subsequent theft.

The Ritz

The Ritz has reported that the scam took place on 12 August and has emphasised that its team would never contact diners with reservations by telephone to request credit card details to confirm a booking.


ID scams and social engineering attacks are becoming more popular and there are measures that can be taken to avoid being scammed.  To avoid being scammed in this way, assume that restaurants (certainly banks) and other businesses will not call to confirm payment details or request authorisation codes. If such a call is received, don’t give any information, end the call and call the company back through the official numbers that you have on any official bills/statements (or the back of your payment card for the bank) or on the company’s main, official number that you have obtained yourself.  Report the call to the company, Action Fraud and the ICO.

What Does This Mean For Your Business?

In this case, the victims were influenced by the apparent legitimacy of the calls due to the correct details of their booking, the same/similar phone number, the convincing nature of the caller, and perhaps the fact that dining at the Ritz is not a regular occurrence and, therefore, booking processes are unfamiliar.  The scammers also had the benefit of the influence of the brand and the need of victims to avoid the discomfort of embarrassment after being told their card had been declined.

This story shows how scammers can quickly, ruthlessly and effectively exploit and leverage a data breach, and is a lesson to customers to always be suspicious of calls from companies about payment details, and to businesses to give data protection a high priority, even with fluid systems that are in regular daily use. This story illustrates how data breaches can damage brands through bad publicity and a potential loss of customer confidence.

Tech Tip – Use The Timeline

If you are using Windows 10 and you need to quickly find a document that you have worked on in the past, using the Timeline can help you to find it and start working where you left off.

To find files using the timeline:

– Either select Task View +? on the taskbar or press Windows logo key +? + Tab.

– Scroll down to find the file you want to return to.

– Select the item to jump back in and carry on working.