Exactly what happens to your body during a heatwave – and the 10 red flags you must never ignore
AFTER a relatively cool summer, the burst of heat hitting the UK this week might seem like a reason to celebrate.
But hot weather has a way of catching us unawares and it can do a number of unexpected things to your body.
With heat health alerts being issued by the UK Health Security Agency (UKHSA) and temperatures expected to soar to 32C in certain parts of the country, some do run a greater risk of harm due to the heat.
People aged over 65 and anyone with pre-existing health conditions - such as respiratory and cardiovascular diseases - especially need to be vigilant as temperatures peak this weekend, as they could be affected by dehydration, heat exhaustion, and in extreme cases, heat stroke.
What happens to your body during a heatwave?
Your body tends to try to keep a core temperature of 37C, but it has to work harder to keep its core temperature down when it's hot.
One of the first things you might notice is sweat.
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This is your body's natural cooling system. Sweat will pool on the surface of your skin and evaporate, drawing the heat away and cooling you down, according to .
You're probably used to receiving warnings about protecting your skin when the sun's out.
That's because exposure to its rays can put you at risk of sunburn, especially if you're not wearing sun cream or not reapplying it enough.
Dermatologists actually advise you do so every two hours if you're out an about in the sun and lather on more if you sweat or take a dip in the pool, as both can decrease its efficacy even if it's waterproof.
But UV rays can also have more long term effects: they can cause your skin to age and sag, or even cause skin cancer.
Something else that can pop up on your skin is a heat rash, also known as prickly heat, which is caused by excessive sweating.
Your sweat glands can get blocked and the trapped sweat leads to a rash developing a few days later.
It's common for babies to get a heat rash because they can't control their temperature as well as adults and children can.
It might surprise you to know that intense heat can even affect your heart.
You might notice that your heart is beating faster when you start to warm up. This comes back to your body trying to maintain its core temperature.
Your heart pumps more blood to your skin, where it can release some of that extra heat, according to WebMD.
This increased blood might even cause your feet and ankles to swell.
You might also get a headache, feel dizzy or even nauseous.
The cause of this is often dehydration, so it's especially important to drink plenty of water when it's hot out.
What red flags should I never ignore?
If you spend a lot of time in the heat or you exercise, there is a risk of getting heat exhaustion, which can progress to dangerous heat stroke if not addressed.
The signs of heat exhaustion include:
- Tiredness
- Dizziness
- Headache
- Feeling sick or being sick
- Excessive sweating and skin becoming pale and clammy or getting a heat rash, but a change in skin colour can be harder to see on brown and black skin
- Cramps in the arms, legs and stomach
- Fast breathing or heartbeat
- A high temperature
- Being very thirsty
- Weakness
If someone is suffering from heat exhaustion, the NHS says you should:
- Move them to a cool place
- Remove all unnecessary clothing like a jacket or socks
- Get them to drink a sports or rehydration drink, or cool water
- Cool their skin – spray or sponge them with cool water and fan them. Cold packs, wrapped in a cloth and put under the armpits or on the neck are good too
They should start to cool down within 30 minutes but you should stay with them until they're better.