Three dangerously unreliable infrared thermometers bought from Amazon and sellers on eBay have failed to measure temperatures accurately in our tests.
All three of the dodgy thermometers provided readings that would lead users to believe they were hotter than they actually were. And we suspect one of them to be a counterfeit product.
The least accurate thermometer - bought from Amazon for £6.37 - reported temperatures that were more than 1.5°C hotter than what they actually were.
With Covid temperature checks a part of our everyday lives, this could be the difference between being permitted to board a flight, getting into a concert or even being allowed into an office or factory to work.
And with cases of the new Omicron variant of coronavirus rising quickly, many people may be on the lookout for a cheap product that can help diagnose a fever.
Our tests also revealed that seven out of eight of the thermometers on test were either missing CE marks or had CE marks that failed to comply with MHRA guidance on markings for a medical device.
Two thermometers that we bought from sellers on eBay and one bought from Amazon repeatedly failed to provide accurate temperature readings across the tests we carried out with them.
Because of this, we've made them Don't Buys. Here are the dangerously inaccurate thermometers to avoid.
We tested this thermometer 44 times across 11 temperature points and we found that the temperatures given were on average 0.64°C too hot. Thermometers are allowed to be out by 0.3°C so this thermometer was twice as inaccurate as it was allowed to be.
We re-tested additional samples twice, but the results provided were just as inaccurate.
Evidence from our test results show that this is the least reliable of the eight thermometers we tested. After 44 temperature tests the readings provided were on average 1.5°C hotter than they actually were.
We retested two identical versions of this thermometer and found the results to be almost the same.
This product was bought from Amazon and branded as the Aicare A66. But upon further investigation - and after contacting the manufacturer of the Aicare A66 - we believe the product we tested is counterfeit.
The instructions were incomplete, key information about how to test the product was missing and the packaging was missing a CE mark. Keep reading for a full response from Aicare.
Wildly variable temperature readings were found with this not-to-be-trusted thermometer.
After our initial round of tests, it was delivering results that were more than 1°C hotter than they actually were.
When we retested another sample, the results were 0.76°C out and when we tested a third sample, the results were 0.37°C away from the target.
All of this suggests poor build quality and components.
The CE mark is a requirement for many products sold in the European Economic Area.
It shows that the manufacturer has checked that the product meets all safety, health and environmental requirements and complies with EU law.
In Great Britain the CE mark will eventually be , which was introduced in January 2021 and will become mandatory in January 2023. But businesses are still able to use the CE mark for products sold in the UK at the moment and that's why we check for it on the products we test.
Digital thermometers are classified as a medical device and the CE marks they carry need to come with a four-digit number linking the product to the organisation (the notified body) that has checked its compliance. Many other products don't need the four-digit number.
As well as three thermometers failing to record temperatures accurately, we found that seven of the eight were either missing CE marks completely or that the CE marks provided didn't comply with the law.
Cofoe KF-HW-001 Infrared thermometer Forehead Digital, £7.89, bought from AliExpress
This cheap thermometer bought from AliExpress passed our 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 we're concerned by the lack of a CE mark. We couldn't find one anywhere.
Infrared thermometer (that Which? believes is a counterfeit of the Aicare A66, £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 our tests. There is a CE mark on the packaging, but it's 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 our 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 our 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.
Four of the five thermometers that passed our tests also came with suspect CE marks. So, a CE mark being missing or wrong doesn't always mean that your product will be unreliable or unsafe, but it is a warning sign that something could be wrong.
Products need a CE mark or a UKCA mark to be legally sold in the UK, so a product without either should not be on sale.
The three thermometers that failed to record temperatures accurately in our tests all came either without CE marks at all, or with something wrong with the CE marks printed on them.
A normal body temperature for an adult is around 37°C.
For babies and children, this will be closer 36.4°C. A high temperature for everyone is 38°C or more.
We 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.
We tested the thermometers to extracts from the 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.
We were unable to set the test mode on the Aicare A66 from Amazon and the JK-A007 Digital temperature thermometer from eBay, so we tested them as a consumer would do in the home.
Following our investigation, the seven thermometers that either failed to record accurate temperatures of that were missing CE marks were removed from sale by the online marketplaces they were being sold through. However, as we went to press, we noticed that one of the eBay listings had reappeared. We asked eBay for it to be removed again.
Sue Davies, Which? Head of Consumer Protection Policy, said:
'Consumers should not have to face a lottery when buying a thermometer online, given these products have taken on a greater importance due to the Covid pandemic and are often marketed as suitable for babies and vulnerable people.
'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.'
We presented our findings to AliExpress, Amazon, eBay and Wish. We also contacted the sellers of the products which failed our tests and the manufacturers.
AliExpress told us: '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 told us: '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.'
eBay told us: '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.'
Wish told us: '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 us that the product tested bearing its logo was counterfeit and it had reported this to Amazon in China. It told us that genuine versions of its A66 thermometer are only available directly from them or through AliExpress.
The seller of the Cofoe KF-HW-001 Infrared thermometer told us that its products are legal, they have corrected the packaging error and that its product now has a CE mark. They went on to say that it has removed its products from the UK.
We asked all of the marketplace sellers to comment. As we went to press, only the seller of the Cofoe thermometer had responded.