Scientists reveal why it doesn't feel hot in UK anymore - as Brits claim they're chilly

Have you noticed that it doesn't feel as hot in the UK anymore, despite what the reading on the thermometer says? 

If so, you've probably become acclimatised to the heat. 

According to Dr Alex Lloyd, a Senior Lecturer in human Factors & Environmental Physiology at Loughborough University, it takes just two weeks for our bodies to get used to heat. 

Speaking to the Daily Mail, he explained: 'The body can adapt to heat, but it needs time. Most people need around one to two weeks of regular, gradual exposure before they are fully acclimatised.' 

The news will come as no surprise to many Brits, who claim they're starting to get chilly.  

Taking to TikTok, @iamtrapnblues said: 'Dare I say it, but is 25°C/26°C starting to feel a bit nippy? 

'It's mad, because back in April we would have killed someone for 26°C. We would have all been in the park sunbathing. But now I'm like, 26°C? I might have to go put on a jumper and a thick pair of socks.'

Replying to the TikToker, one viewer said: 'Alexa told me its highs of 29 today I immediately thought ah that will be nice its cool today,' while another joked: 'Got a bbq Saturday, it's gonna be 25 and I'm wondering if they're gonna call it off.' 

As the UK's relentless heatwave continues, many Brits have taken to TikTok to discuss their unusual reactions to the sustained heat. 

@courtneyaucott said: 'Is it just me, or is 24, 25, and 26°C starting to feel a bit chilly?

'I left the house in my trousers and jacket today. I just think it's mad, because 26°C is still hot – so why am I feeling cold?'

@jaydensalaam added: 'Does it not feel like the weather is feeling cold again? When I went outside yesterday, I was feeling chilly!'

And @mentalwealthlabs said: 'When I sleep, I have to put my blanket on me because I get too cold.'

According to Dr Lloyd, these chilly Brits are experiencing something called 'heat acclimatisation'. 

'Heat acclimatisation is a well–established physiological process by which the body "learns" to better tolerate high temperatures through repeated exposure,' he explained. 

At the start of the heatwave, most Brits had little or no baseline heat acclimatisation, thanks to the UK's temperate climate.

However, following weeks of sustained heat, many of our bodies have started to make adaptations to cope. 

This includes increased sweating efficiency, plasma volume expansion, enhanced skin blood flow, and reduced perceived effort when exercising.  

'Together, the mechanisms help to lower heart rate and core temperature, as well as increase our tolerance, during heat exposure,' Dr Lloyd said. 

To acclimatise properly, you need to be exposed to heat on a daily basis for around two weeks.

However, the effect does not last indefinitely. 

Dr Lloyd said: 'After a week or more away from heat, some of the adaptation can start to fade, so people may need to acclimatise again.'

While you might feel more accustomed to the heat, Dr Lloyd warns that prolonged heat exposure can still be dangerous. 

'Prolonged heat exposure can cause a range of health problems, from relatively mild symptoms such as cramps, dizziness and heat rash to serious conditions including heat exhaustion, muscle breakdown and heat stroke,' he said. 

'Early signs can include swelling in the hands or feet, painful muscle cramps, fainting or dizziness, and heat rash.

'More serious cases include heat exhaustion, which can cause heavy sweating, fatigue, nausea, dizziness and a fast heart rate. 

'In severe cases, heat can contribute to muscle breakdown, which can damage the kidneys and disturb the body’s salt balance.'