Dangerously inaccurate thermometers sold on biggest online shopping sites, Which? warns

Infrared thermometers sold on popular online marketplaces, including Amazon and eBay give dangerously inaccurate temperature readings, suggesting they have not been adequately checked or safety monitored by the online platforms, according to a Which? investigation. 

The consumer champion is concerned about the consequences for people using these devices. Parents buy them to help check if their babies are ill, while for adults, Covid temperature checks have become a part of everyday life, and could be the difference between being allowed to board a flight or enter an office.

Which? bought eight non-contact ‘gun’ style thermometers from AliExpress, Amazon, eBay and Wish, all sold for under £10, and carried out hundreds of temperature checks with them. Experts found that three of the eight were wildly inaccurate and could lead users to believe they were hotter than they actually were.

All of the thermometers Which? looked at featured near the top of the online marketplaces’ listings for obvious search terms such as ‘forehead thermometer’.

Two thermometers Which? bought from sellers on eBay and one from Amazon repeatedly failed to provide accurate temperature readings. Which? has named these products as ‘Don’t Buys’ and considers them to be dangerously inaccurate thermometers that consumers should avoid.

This follows a Medicines and Healthcare products Regulatory Agency (MHRA) warning in July this year about an increased rise in the number of inaccurate infrared thermometers making their way onto the UK market – believed to be caused by the Covid-19 pandemic creating a massive increase in demand for these products.

Concerningly, seven of the eight products Which? tested, even the ones that provided more accurate temperature readings, were also either missing CE marks completely or the CE marks provided did not comply with the law. These marks are meant to show that the manufacturer has checked that the product meets all safety, health and environmental requirements.

An infrared thermometer, bought from Amazon for £6.37 and with almost 2,000 customer ratings, was the least reliable of the eight thermometers tested. After 44 temperature tests the readings provided were on average 1.5°C hotter than they should have been.

A normal body temperature for an adult is around 37°C. For babies and children, this will be closer to 36.4°C. A high temperature for everyone is 38°C or more – so this thermometer could indicate that someone is really unwell when they are not.

This product was branded as the Aicare A66 on the Amazon listing Which? bought it from. However upon further investigation – and after contacting the manufacturer of the Aicare A66 – Which? believes the product it tested could be a counterfeit. The instructions were incomplete, key information about how to test the product was missing and the packaging was missing a CE mark.

A KRK non contact infrared thermometer, bought from eBay for £8.59 was tested 44 times across 11 temperature points and the temperatures given were on average too hot by 0.64°C. According to the British Standard (BS EN ISO 80601-2-56:2017+A1:2020) thermometers are allowed to be out by 0.3°C, on average across all the tests.

A JK-A007 Digital temperature thermometer, bought from eBay for £6.89, also had wildly variable temperature readings. After the initial round of tests, it was delivering results that were more than 1°C hotter than the correct reading. When experts retested another sample, the results were 0.76°C out and when they tested a third sample, the results were 0.37°C away from the target. All of this suggests poor build quality and components.

For all but one of the eight thermometers investigated, there was either no CE mark at all or there was a CE mark on the product missing key components, such as the four digit code showing that it has been independently checked by a notified body – which is required for medical devices. This is yet another worrying indication of the lack of checks and monitoring carried out by online marketplaces.

In Great Britain the CE mark will eventually be completely replaced by the UKCA (UK Conformity Assessed) mark, which was introduced in January 2021 and will become mandatory in January 2023. However businesses are still able to use the CE mark for products sold in the UK at the moment.

The online marketplaces said that they had removed the products with issues that were flagged as available on their sites by Which?, seven in total.

The Office for Product Safety and Standards’ (OPSS) recent response to its Product Safety Review acknowledged the problem of unsafe products sold on online marketplaces. The government has also tested more than 1000 products sold online in the run up to Christmas and issued its own safety alert highlighting the product safety risks when shopping on marketplaces.

It is good that the OPSS has stepped up its activities on online product safety, however as more people shop online and use these platforms, swifter and stronger action is needed to deal with the clear and serious dangers present in this market.

Which? believes the government needs to do more to prevent unsafe products being sold  online by bringing in tougher laws and regulations to make online marketplaces legally responsible for dangerous products offered through their sites.

Consumers should be wary of cheap thermometers sold on online marketplaces. Consider paying a bit more and buying from a reputable brand and retailer to ensure it gives out accurate temperature readings. Which? has tested models that are accurate and cost £20.

Sue Davies, Which? Head of Consumer Protection Policy, said:

“Consumers should not have to face a lottery when buying a thermometer online, particularly given these products have taken on a greater importance due to the Covid-19 pandemic.

“The government and regulators have recognised the problem of unsafe products sold on online marketplaces but they must take robust action to crack down on this issue now.

“The government must bring in tougher laws and regulations to make online platforms legally responsible for unsafe products offered through their sites.”


Notes to editors 

How Which? tests infrared thermometers:

Which? tested a selection of eight infrared (non-contact) thermometers bought from online marketplaces following a warning by the MHRA (Medicines and Healthcare products Regulatory Agency) highlighting safety and performance concerns in July 2021.

Which? tested the thermometers to extracts from the medical electrical equipment standard (BS EN ISO 80601-2-56:2017+A1:2020).

Products on test are permitted to be on average 0.3°C out on average after 44 temperature readings taken at 11 different temperatures between 35°C and 40°C.

Test modes are available on digital thermometers to allow them to be accurately tested to the official standard. Six of the thermometers on test were set up in their test modes.

Which? was unable to set the test mode on the product that was branded as the Aicare A66 on the listing, but Which? believes could be a counterfeit, from Amazon, and the JK-A007 Digital temperature thermometer from eBay, so these were tested as a consumer would do in the home.

The CE mark issues uncovered on seven of the thermometers: 

Cofoe KF-HW-001 Infrared thermometer Forehead Digital, £7.89, bought from AliExpress

This cheap thermometer bought from AliExpress passed Which?’s temperature tests but there was no CE mark found on the packaging, the product or the instructions.

Landwind LW FT118 Infrared thermometer, £7.99, bought from a seller on Amazon

Another thermometer that delivered accurate temperature readings but Which? is concerned by the lack of a CE mark. Which? couldn’t find one anywhere.

Infrared thermometer (branded as the Aicare A66 on the listing but Which? believes could be a counterfeit), £6.37, bought from Amazon

The most inaccurate thermometer on test also comes with non-complaint CE marks on the product and the instructions, which fail to include a four digit code linking the product to the company that carried out CE mark checks on it. All of this adds to the picture about how dodgy this product could be.

Non contact infrared forehead thermometer, £7, bought from Wish

This thermometer was accurate in Which?’s tests. There is a CE mark on the packaging but it is too small and there were no CE marks on the product or the instructions. There’s also no four-digit code linking the product to the notified body that checked it.

Dikang HG01 Medical Infrared Forehead Thermometer, £7, bought from Wish

The product, the box it came in and the instructions for use were all missing CE marks. So, even though this accurate thermometer passed Which?’s temperature tests, it still shouldn’t be sold.

KRK non contact infrared thermometer, £8.59, bought from eBay

Not only was this thermometer unable to reliably provide correct temperatures in Which?’s tests, it’s also missing all of the required CE marks.

JK-A007 Digital temperature thermometer, £6.89, bought from eBay

This unreliable thermometer comes with a CE mark but it’s missing the four digit code showing that it has been independently checked by a notified body.

How to accurately measure someone’s temperature using a digital thermometer:

  • Read the instructions provided with the thermometer and make sure that it’s set up to take the temperature of a person. Many of these products come with modes to take the temperature of people or rooms, so make sure it’s set up in the correct mode first.

  • Make sure the thermometer, particularly the lens part that emits the infra red, is clean and free of dirt, dust or moisture. If you need to clean it, use a cotton bud and some water.

  • If you’ve just done something to make you hotter than normal – such as exercise, a hot bath or even drink a hot drink – wait 15 minutes before taking your temperature.

  • Your forehead is the place to aim for with gun style infrared thermometers. So, if you have a fringe or long hair falling down over your face, push your hair back or to one side. However, you can also scan the armpit or wrist.

  • Make sure it’s close enough to get a reading – a distance of around 5-8cm is usually fine.

Rights of reply:


‘The safety of all our customers is our key priority. After being notified by Which?, we have removed the item identified in their investigation from our platform in the UK. We are examining the items and working with the sellers to ensure the correct documentation is provided and that they meet the required safety standards. We have strict platform rules that require all third-party sellers to comply with all applicable local laws and regulations.’

An Amazon spokesperson said: ‘We invest significantly to ensure that customers receive safe and authentic products when shopping on Amazon. We have proactive measures in place to prevent suspicious or non-compliant products from being listed and we monitor the products sold in our stores for product safety concerns. When appropriate, we remove a product from the store, reach out to sellers, manufacturers, and government agencies for additional information, or take other action. If customers have concerns about an item they’ve purchased, we encourage them to contact our Customer Services directly so we can investigate and take appropriate action. The products in question have been removed.’


‘We have removed the listings identified by Which and taken action against the sellers’ accounts. We take the safety of our users very seriously and have manual processes and automatic block filters in place, which have prevented millions of unsafe listings. If something does make it onto site, we act quickly to remove it and provide product safety education to sellers to prevent relisting.’


‘We are committed to creating a fun and engaging shopping experience that is also safe for our users. After learning that these two listings did not comply with local standards, which is a violation of our Merchant Terms of Service and Policy, we took prompt action to remove them from the platform.’

Aicare told Which? that the product tested bearing its logo was counterfeit and it had reported this to Amazon in China. It said that genuine versions of its A66 thermometer are only available directly from them or through AliExpress.

Which? asked all of the marketplace sellers to comment. As Which? went to press, only the seller of the Cofoe thermometer had responded.

The seller of the Cofoe KF-HW-001 Infrared thermometer told Which? that its products are legal, it has corrected the packaging error and that its product now has a CE mark. It went on to say that it has removed its products from the UK.

About Which?

Which? is the UK’s consumer champion, here to make life simpler, fairer and safer for everyone. Our research gets to the heart of consumer issues, our advice is impartial, and our rigorous product tests lead to expert recommendations. We’re the independent consumer voice that influences politicians and lawmakers, investigates, holds businesses to account and makes change happen. As an organisation we’re not for profit and all for making consumers more powerful.

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