How much water should you drink in the heat? (Picture: Alamy)

Water makes up about 66 per cent of the human body, it runs through our blood, inhabits the cells and even lurks in the spaces between.

Poor hydration has been linked to a wide variety of serious health issues, including heat exhaustion, heat stroke, heart disease, lung problems, kidney disease, bladder and colon cancer as well as dental issues.

Low fluid intake can increase morality rates among older adults, according to a 2010 British Nutrition Foundation study.

Temperatures have already reached above 30°C this week – and it’s only getting hotter – so staying hydrated is extremely important.


But you can also drink too much water, so how much is enough?



How much water should you drink a day?

Most of you will be familiar with the advice to drink eight glasses of water per day.

This remains the official health position in the UK, with the Government’s Eatwell guidelines recommending six to eight glasses.

Older and very young people are more vulnerable in the heat (Picture: AFP)

But there’s one small problem. A ‘glass’ isn’t a standard unit of measurement. It’s easier to measure your water intake in more practical terms.

Eight litres is around two litres, or three and a half pints.

This is enough to replace the water your body loses every day through processes such as sweating, urinating and breathing.

How much water should your child drink?

Children have a higher ratio of water in their bodies than adults, which makes staying hydrated even more important for them.

According to the British Nutrition Foundation, it also means that even though they’re smaller, children still need the same amount of water as adults.

It’s important to monitor your child’s water intake carefully and ensure they’re regularly rehydrating.

This is extra important during the summer when the weather is warmer, or if your child spends a lot of their day running around.

Staying hydrated is extra important in the heat (Picture: Alamy)

How do you stay hydrated in hot weather?

Avoiding dehydration is very important and you’ll need to take extra care in hot weather.

When you’re dehydrated, it means your body loses more fluid than it’s taking in. The mineral balance of your body is upset and it can’t function as normal.

Left unchecked, it can lead to kidney stones, constipation, heat exhaustion and heatstroke.

You’ll know if you’re dehydrated, because many of the symptoms are pretty obvious.

Feeling thirsty is your first warning. If you’re feeling a little parched, you’ve lost around 1 per cent of the water in your body. Lose 2 per cent and you’re officially dehydrated.

You should also look out for signs such as feeling tired or faint, muscle cramps, infrequent urinating and very dark urine.

To avoid getting dehydrated on a hot day, you simply need to drink a little more water than you would normally, particularly if you’re sweating a lot.

Remember, if you’re feeling thirsty then you’re already starting to dehydrate, so take regular sips of water to stop this happening.

If you’re planning on exercising, make sure you’re well hydrated before you start.

Water makes up about 66 per cent of the human body (Picture: PA)

How can you get the water you need?



Around 20 per cent of your daily water intake will actually come from food.

All of the juicy fruit and vegetables you should eat as part of a healthy diet can help to hydrate your body and are a lot tastier than a plain old glass of water.

When it comes to drinks, milk is actually the best choice for hydration.

A 2015 BBC science programme confirmed that milk absorbs more slowly into your intestines, which means it stays in your body for longer.

Sodium and potassium are both found in milk, but no water.

Alcohol and caffeinated drinks are strong diuretics, which means they’ll make you pee more frequently than normal.

Is it possible to drink too much water?

Yes. This is a problem that can affect athletes who drink a lot of water while they’re exercising.

We know that our bodies lose water when we sweat, so surely it makes sense to rehydrate regularly during a run?

However, we also know that sweat contains important electrolytes that aren’t found in water, such as sodium. By only refuelling with water and drinking way above the recommended daily limit, you could dilute your blood to a dangerous degree.

You can drink too much water (Picture: Getty Images)

When this happens it can lead to a very dangerous condition known as hyponatremia. It can cause issues with your brain and even be fatal.

If you’re planning to exercise for longer than an hour, you should swap plain water for an isotonic sports drink. This will ensure you’re topping up your nutrients while you rehydrate.

Water helps your body perform basic functions

Water does so many important things for your body. You probably don’t even think about them most of the time.


It keeps your eyes moist, lubricates your joints and helps with digestion and waste removal.

If any of these processes went wrong, you would notice.

Sweat is another example of water helping to keep you alive.

When it happens, your body is actually taking heat away from your internal organs, where it could do serious damage.

Water also helps keep your blood circulating, which is important for transporting nutrients around your body to where they’re needed.

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