How to

21 June 2017

Why Hot Weather Can Leave You Feeling Fatigued

It’s not too often that we’re graced with extremely warm weather in the UK, and when we are we’re not always sure what to do about it. Trips to the beach and afternoons spent sunbathing are always great ways to spend your time, but being in the sun for too long can leave you feeling exhausted.  Even if you’ve done nothing particularly strenuous, the hot weather can drain you of your energy and have you craving a nice, long sleep.

Why is that?


Warm weather and sunshine can cause you to sweat as your body tries to maintain its internal temperature and keep you from overheating. While this process is beneficial, it does mean that fluid and salts are being lost in sweat and this can lead to dehydration.

What’s one of the primary symptoms of dehydration? Fatigue.

It’s important to ensure that your fluid intake is frequent during bouts of hot weather to prevent this from happening. Drink plenty of water and familiarise yourself with the other symptoms of dehydration – headache, dizziness and dry mouth.

Temperature Regulation

Your body puts in a lot of effort to keep you cool, even if you don’t realise it. A rise of just 0.5° in your body’s internal temperature can cause irritability and tiredness, particularly in children, so it has to work hard to prevent this.

When exposed to sunlight and high temperatures, your body tries to find ways of dealing with the heat, hence the process of sweating mentioned above. It does more than just that, though. Your heart and metabolic rates are often increased to cope with the warm weather, resulting in a lot of physiological effort on your body’s behalf. It’s the combination of all these factors that can lead to feelings of fatigue.

Chemical Changes

Hot weather almost always means bright sunshine that’s perfect for topping up a tan (or turning a bright shade of red), and that is part of the reason why you can often feel fatigued during the summer months. Exposure to the sun’s ultraviolet rays can cause a whole host of chemical changes in your body which end up leaving you feeling exhausted after just a few hours of doing next to nothing. This is believed to include a suppression of melatonin production which is then increased several hours after being in the sunshine, as well as a boost in positive vitamins.

Staying safe in the sun is something that has been heavily documented in the past and we’re all aware of the basics when it comes to reducing the harsh impact of hot, summer weather.  By understanding what it is about higher temperatures that leads to tiredness, it can be easier to combat it. Spending time in the shade, using sun cream and wearing sunglasses and other protective clothing are all great ways to protect yourself from the sun and therefore help prevent the onset of fatigue. 

James Darvill

James is a passionate scriptwriter and reluctant poet with a talent for the dystopian. When he’s not staying up late watching the Simpsons he’s beating the world at Mario Kart, always with a glass of wine in hand.