SCORCHING temperatures forecast for the weekend ahead will have many reaching for their hats and sunscreen.

Brits are hotly anticipating the first of the year, which could see the mercury soar to highs of 31C, according to the Met Office – making it hotter than .

Woman taking a selfie in a park filled with daisies.Brits can expect soaring temperatures over the next few days Credit: Reuters NINTCHDBPICT001082646103Credit: Met Office

The expects a heatwave from Friday until Tuesday, with .

Central and western and parts of will slowly warm up too as the weekend progresses, with highs of 28-29C predicted.

But sunburn isn’t the only concern you need to be mindful of.

For millions of Brits, there is a darker side to the glorious as the heat can interfere with some – in some cases, with life-threatening consequences.

Red double-decker bus blurring past historic buildings and modern skyscrapers in London.London is expected to be hotter than Spain on Sunday Credit: Karl Hendon NINTCHDBPICT001082635112The southeast is expected to feel the warm spell first, before it spreads across the UK Credit: Met Office

The UK’s drug regulator the Medicines and Healthcare products Regulatory Agency (MHRA) has previously warned that some medicines and treatments can change how you respond to sun and heat.

For the eight million Brits taking medications like , for example, high temperatures can turn their from helpful to harmful.

Around five million of those are prescribed selective serotonin reuptake inhibitors (), commonly used to treat conditions like and anxiety.

And they’re not the only affected – ADHD medications, some antibiotics and drugs to treat blood pressure can also make it harder to cope in warm .

These drugs can be lifesaving for many, but they can also make the body more vulnerable to heat.

“They can stop the body from regulating temperature properly,” pharmacist Thorrun Govind tells Sun Health.

SSRIs, like and work by increasing serotonin levels in the brain – a natural chemical that regulates mood.

By upping the level of serotonin, these drugs can help make people feel happier.

But because these medications influence the brain’s chemicals, they also affect the hypothalamus, the part of the brain that acts as the body’s thermostat.

The build-up of serotonin can make the hypothalamus less effective at sending the signals needed to control body temperature.

“This can lead to excessive sweating,” Thorrun adds.

“This can be counterproductive in hot weather as the body is already struggling to cool down.”

How to keep your medicines safe in the heat

By Dr Sameer Sanghvi

You also need to be mindful of where you’re storing your medications, especially in hot weather.

Heat, air, light and moisture can all damage your medicine and stop them working as they should.

Medications are likely to expire more quickly if not stored correctly too.

A drawer or cabinet is an ideal place to store medicine.

These tend to stay cool and dark, even in warm weather.

That said, I’d avoid keeping your medicine in bathroom cabinets as these can become very damp thanks to steam from baths and showers.

Unless advised otherwise, you should always keep medication in its original packaging.

Things like the box and blister packet that tablets come in are designed to protect the medicine inside so it can do its job effectively.

Woman in a red blazer smiling outdoors.Pharmacist Thorrun Govind warns some drugs make the body more sensitive to heat

Excess sweating can lead to and, paradoxically, a rise in body temperature.

Worryingly, another type of antidepressant, , can also affect brain function, making it harder to spot the early signs of overheating, like dizziness, confusion, or .

They can also make you sweat less as they block a chemical in the body that helps activate sweat glands, making it harder for your body to cool down.

“In some cases, this disruption can be life-threatening when your body struggles to cope with the soaring temperatures,” Thorrun says.

One of the most serious risks of extreme heat is – a medical emergency that occurs when the body overheats and can no longer cool itself down.

“I’ve actually experienced myself, and it’s a real shock to the body – you feel completely out of it,” Thorrun adds.

Your internal body temperature typically stays around 37C, because that’s the range your organs need to function properly.

Heat sets in when it rises to 40C or higher. This is when it can quickly become dangerous – leading to confusion, , organ failure, and, in severe cases, death.

Senior woman fanning herself, looking unwell from the heat.Brits need to be mindful of what medicines they are taking during the heatwave Credit: Getty

How to stay safe

“If you are taking these kinds of antidepressants, first things first, do not stop taking them,” Dr Sameer Sanghvi, a at LloydsPharmacy Online Doctor says.

“You should always consult your doctor before making changes to your medication.”

The best thing people on these medicines can do is to take precautions, he says.

“Try to stay cool by sticking to the shade, drinking plenty of fluids and by avoiding alcohol,” Dr Sameer explains.

can make you feel hotter because it dehydrates you and increases blood flow to the skin, making it harder for your body to cool down.

“You should also keep out of the sun between 11am and 3pm, avoid exercising in the hottest parts of the day and wear loose, breathable clothing,” he adds.

The MHRA also offers some tips to help people stay safe and well throughout the summer when it comes to medicines.

Store medicines below 25C

  • Avoid leaving medicines in direct sun, hot cars, travel bags, or on sunny windowsills – temperatures can easily exceed safe storage limits and degrade tablets, inhalers, insulin, EpiPens and more. 
  • If you spot changes in smell, colour, texture, or performance of your medicines, consult a pharmacist. 
  • While travelling, keep your medicines in a cool bag or stay in temperature-controlled environments.

Check your medicines and devices in the heat

  • Even well-sealed medical devices – like blood glucose monitors – can misread if exposed to excessive heat or humidity. 
  • Stay cool, keep devices dry, and run periodic control checks.
  • Be alert during heatwaves: some medicines can worsen dehydration or impair temperature regulation, including diuretics, drugs, treatments, antipsychotics, and stimulants. 

What are the symptoms of heatstroke?

IF you sit out in the sunshine for too long, you might experience something called “heat exhaustion”.

This is the body’s natural response to overheating, caused by an excessive loss of water and salt, usually through excessive sweating.

When this happens you may experience , dizziness and confusion, feeling sick and cramps – which can be easily mistaken for heatstroke.

However, for heat exhaustion, the NHS says your symptoms should clear within 30 minutes of cooling down.

Heatstroke, on the other hand, is more dangerous and lasts longer (but is thankfully, much less common).

There is cause for concern when you start to exhibit these five extreme symptoms, as they may be signs of heatstroke:

  1. Feeling confused
  2. Becoming unresponsive or losing consciousness
  3. Having a fit or seizure
  4. Having a temperature above 40C
  5. Having rapid or irregular breathing

The NHS recommends that you call 999 if you exhibit these symptoms.

The 3 other drugs that can be dangerous in the heat

As temperatures rise, it’s not just antidepressants that can be affected by the heat.

“Living in the UK, we’re more used to grabbing our umbrellas than worrying about how our medicines change in the sun,” Thorrun says.

Here are some other common medications you might have at home that can pose similar risk:

1. Blood pressure drugs

Around 8 million people in the UK are on medication for , including diuretics and beta-blockers.

These drugs can make it harder for the body to handle heat because they affect fluid levels and heart rate.

“This makes it harder for the body to sweat and cool down. Without enough fluid, your body can struggle to regulate its temperature, leaving you at greater risk of heat stress,” explains Thorrun.

Diuretics, for example, make people need to pee more, leading to dehydration.

ADHD medication spilled from pill bottles.Medicines used to treat ADHD, or attention deficit hyperactivity disorder, can raise core body temperature Credit: Getty

2. ADHD meds

Medicines used to treat , or attention deficit hyperactivity disorder, can raise core body temperature.

This is particularly true for methylphenidate, which is one of the most commonly prescribed stimulant medications for ADHD.

“It can stop your body’s ability to cool itself,” says Thorrun.

This can make it more difficult to stay cool during hot weather, increasing the risk of overheating and heat stroke.

3. Antibiotics

Doxycycline is one of the most commonly prescribed in the UK – typically dished out to treat skin conditions and infections such as acne.

However, it can make your skin more sensitive to sunlight, increasing the risk of sunburn and skin reactions – even after short bursts in the sun.

Thorrun says: “This is more about sunlight than heat, but it can still be dangerous in intense sun.”

Frequent means you are more likely to get – which kills six Brits every day.