How to keep cool in hot weather and stay hydrated during a heatwave

It's hot today, have you noticed?

Aah the weather, Londoners' favourite topic of conversation. How many people have mentioned it to you so far today - five, 10, 15 plus? And what do these conversations centre on - how uncomfortable it is? How hot the tube was? How you wish you could spend the day outside basking in the sun...?

What's probably not at the forefront of these conversations, which really needs to be, is how to stay hydrated. Many of us aren't used to leaving the house with a water bottle in-hand, but with temperatures expected to reach the high 20s all week this week, it's imperative Londoners are prepared.

Not sure how to go about that? Or just, how to stay cool in general? Here's what to know about keeping cool and hydrated in the city this summer...

Keep a water bottle on you

Yes, this is fairly obvious, but as above, it's so easily forgotten.

Since we're not about plastic bottles these days, purchase a reusable one - and make sure you keep it topped up all day.

How much should you drink?

Dr Kim Glass, Lead GP at Bupa Health Clinics, says: "As a basic guide, we should drink 1.5 to 2 litres of fluid a day, which is about eight to 10 glasses. However, if you’re in the heat during the day you can become dehydrated quicker, so drink more often and aim for at least 2 litres.

"It’s very unlikely that you’ll drink too much water, but if you're going to the toilet a lot and your urine looks really pale, you’re probably drinking more than you need."

She adds, "If you’re sweating a lot due to heat and begin to feel signs of dehydration then, as well as replacing your fluids you may find you need a recovery drink such as an electrolyte or low-sugar energy drink."

What should we be drinking?

Water is the best option, but if you'd rather something with a little more flavour, add some citrus - lemon, lime, orange - or perhaps cucumber and mint.

Coconut water is a good alternative to straight water, as are fruit juices - just watch out for the sugar content and don't drink them if you have diarrhoea or are vomiting as it could make it worse.

Avoid alcohol too - that will only dehydrate you further.

How do I know if I'm dehydrated?

Dr Kim says, "Our bodies can become dehydrated before we see any obvious signs so always keep your fluids topped up, before you feel thirsty.

"If you do feel thirsty, chances are your body’s telling you that you need to drink more. But the best indicators are the number of times you go to the toilet and the colour of your urine – it should be pale yellow. If you don’t need to go often, you only pass a little each time and it's dark in colour, it’s likely that you’re dehydrated."

Other signs of dehydration include headaches, dry mouth, lips and/or eyes, cramps and feeling tired, lightheaded, dizzy and/or confused.

What do I do if I think I'm dehydrated?

"Grab yourself a drink," says Dr. Kim. "For mild dehydration, it’s best to drink small sips of water and often, rather than trying to drink a lot all in one go because this may make you vomit.

"If your dehydration causes you to have diarrhoea or vomit, you’ll also be losing important salts and sugars from your body. A good way to replace these is with rehydration sachets, which you can buy over the counter. Some people choose sports drinks but these contain much more sugar than you need so it’s best to stick to rehydration sachets.

"If you have more severe dehydration, visit your GP for advice."

How to keep cool in the heat...

There are an infinite number of ways, however the tips below are a good place to start. Most important of all though is to remember to wear sunscreen if you're planning to be outside.

1.) Carry around an ice pack or, if you don't have one, a frozen drink. It might not be practical - it'll drip as it melts - but it's guaranteed to instantly cool you down.

2.) Run your wrists under cold water - that'll help to cool the blood.

3.) This isn't rocket science but wear loose cotton clothes in light colours. Cotton is lightweight and breathable - synthetic fibres trap heat - and it also absorbs sweat. Light colours too reflect the sun's radiation.

4.) Use something to fan yourself that isn't your hands. The flapping motion not only uses up energy but will likely make you hotter in the process as well.

If you don't own a fan, use paper or something flexible; anything that doesn't require too much work to get the air moving.