Doctor reveals exactly how much water you need to drink in a heatwave

It is absolutely steaming in the UK right now, and with high temperatures come a heightened risk of dehydration.

When it’s hot out and we’re feeling lethargic it can be tempting to forgo the sun screen and hydration, but it’s vital that you lather up and drink up to keep yourself healthy. It’s important to take breaks from direct sunlight as well, as heat exhaustion and sunstroke are neither fun nor safe.

Dehydration can strike at any time of the year, but it’s particularly likely in hot temperatures.

Dehydration has a host of unpleasant side effects that get worse as it progresses (Nico De Pasquale Photography/Getty Images)

You sweat an awful lot more, so your body loses water at a faster rate than it would in the chillier months, and when your hydration levels drop you’ll encounter all kinds of nasty effects.

Increased thirst, light-headedness, fatigue, sunken eyes, yellow and bad-smelling urine, a dry mouth, headaches, and a general sense of unease are all par for the course when you’re short on water, and these all compound as the problem gets worse.

However, the answer isn’t to constantly chug water as that can be a bad call too.

So, what’s the right amount of hydration?

As a baseline, we should be drinking around two litres of water per day, and that need increases with exercise levels and temperatures. Other factors can play a role, too, and some doctors recommend drinking considerably more than two litres each day.

“It is well known that most individuals do not consume enough water,” said Dr Angela Rai, GP at The London General Practice, per the Independent. “It is recommended to drink around eight glasses of water per day, which equals around 1.5-2 litres per day.

“The ideal water intake varies on factors such as age, underlying health conditions, medicines taken regularly, and activity levels, but in general men may need up to 3.7 litres a day and women 2.7 litres a day.”

Dr Rai then stressed that the heat significantly increases the amount we need against this baseline.

Everyone has their own water needs, with factors like age and gender playing a role (Dougal Waters/Getty Images)

“We need to drink up to around three litres a day (not including hidden sources) to replenish fluids we lose through sweating,” she said.

“It is important to space this out throughout the day and not to drink excessive amounts all at once. Start your day with a glass of water first thing in the morning to help rehydrate your body after sleep.

“If you are working in the heat, try to drink around one cup of water every 20 minutes.”

Stay safe out there.