Even the young and fit are encouraged to skip the runs and many beers in the heat wave.

Ahead of England’s World Cup match against Panama on Saturday, people are being advised to drink plenty of fluids but not too much alcohol to avoid dehydration in the punishing heat.

Alcohol is a diuretic, which means it flushes you out more, and hot weather makes us sweat more.

“This double dehydration makes it even more important to drink plenty of water and stay hydrated throughout the day as much as possible,” says Alcohol Chance UK.

Nights are also hot during heat waves, which presents its own challenges. It means that the body cannot cool down in the middle of the day.

Heat exhaustion It can affect anyone, including healthy and fit people – especially if you do strenuous exercise in extreme heat or drink alcohol all day in the sun. It can come on quickly, in minutes or slowly over hours.

It can be changed later Increase in temperature, ExternalThis is a medical emergency. This means that your body cannot regulate its heat and your core temperature rises too high. There may be rapid breathing or shortness of breath and collapse or loss of consciousness. Get immediate medical attention.

People are remembering that it’s best to take a couple of days off to exercise given the heat. If you’re going to do something physical outdoors, dial it down, slow down, and schedule it for a cooler time of day, like early morning or late evening, experts recommend.

Paris Mayor Emmanuel Grégoire told French TV that people should not believe they are “invincible”.

“I’m thinking especially about the young people…I’ve seen about 100 runners on the road. It’s irresponsible to be honest.”

London’s Ambulance Service said it responded to life-threatening emergencies as temperatures in the UK capital hit the mid-30s on Wednesday.

Compared to a typical Wednesday in June, there was a 50% increase in life-threatening emergency calls, and a 30% increase in cardiac arrests.

Chief operating officer Craig Harman is advising people to drink plenty of water between alcoholic drinks, as football fans prepare to enjoy England on Saturday, with temperatures expected to still top 30C.

“I want you to drink water even if you are not thirsty, I tell people to avoid the sun during the hottest part of the day and especially not to exercise outdoors and not to expose your body to additional heat and stress.

“Young people are also suffering from cardiac arrest,” warned French Health Minister Stéphane Rist.

Ambulance services in Paris saw four times the normal number of cardiac arrests in a 24-hour period, although there is no confirmed death toll linked to the heat wave yet.