What are the signs of heat exhaustion?

Find out what to look out for, and what to do if you recognise them

Health Advisor

14 June 2016

What is heat exhaustion?

Heat exhaustion is a condition that occurs during hot temperatures, and it is often accompanied by dehydration. As temperatures increase the body begins to warm up, and produces more sweat in an attempt to cool down. During this process both water and salt is lost, which can begin to cause problems if they are not replaced. 

If not identified and treated correctly, heat exhaustion can sometimes turn into the much more serious heat stroke.

What are the signs of heat exhaustion?

It is important to identify the signs of heat exhaustion early on so that you can prevent the condition from becoming an emergency.

Signs of heat exhaustion as a result of water loss include:

  • Excessive thirst
  • Dark coloured urine
  • Fatigue or weakness
  • Headache
  • Dizziness and fainting

Signs of heat exhaustion as a result of salt loss include:

  • Nausea and vomiting
  • Muscle cramps (See heat cramps)
  • Dizziness

If you develop heat exhaustion it is likely that you will experience a combination of these symptoms, since water loss and salt loss tend to go hand in hand when temperatures are high, since both are lost in our sweat.

What to do if you notice these symptoms

If you notice any of these symptoms and suspect you have heat exhaustion, it is important to act quickly to prevent the condition from worsening. The most important things to do are to cool down and replace your fluids and electrolytes as quickly as possible.

  • Get out of the heat and into an air-conditioned room. If no air conditioning is available, take a cool bath or shower. If these aren’t available use whatever you can to cool down – wet flannels, wet towels, ice packs, fans. Top tip: fanning wet skin will help the body cool down faster!
  • Remove any tight, heavy or unnecessary clothing. Switch to light cotton, or even your underwear or swimwear (though exposing bare skin to direct sunlight will make this condition worse, so make sure you do this once you’re inside or in the shade)
  • Drink plenty of water – make sure to avoid caffeine, fizzy drinks or alcohol
  • Replace electrolytes. It is vital that you replace electrolytes such as sodium, magnesium and potassium as these can be lost when you sweat. Sports drinks are good for this, but they also contain high levels of sugar and artificial chemicals. If you can, opt for coconut water or birch water as these naturally contain electrolytes and natural sweeteners. If these aren’t available then fruit juice will help too. If you happen to have it, A.Vogel’s Balance Mineral Drink also contains electrolytes so would be useful – might be something to pack for your next holiday!

Even once you have recovered from heat exhaustion, it is important to avoid high temperatures and strenuous exercise for the next week, and ensure that you keep your fluid intake up every day.

When to seek medical help

If your symptoms don’t improve after 30 minutes of cooling down and drinking fluids, or your symptoms rapidly begin to get worse, seek medical assistance immediately to prevent the development of heat stroke.

How to reduce your risk of developing heat exhaustion

While heat exhaustion is fairly common – especially for us Brits on holiday – it is still a serious condition and should not be taken lightly. 

When out and about in hot weather, it is important to keep cool and keep hydrated to avoid developing heat exhaustion. Here are some tips:

  • Avoid being in the sun during the hottest part of the day (11-3). Instead sit in the shade or inside. When out in the sun wear a wide brimmed hat
  • If you can, bring a fan outside with you to keep cool. If not, applying a wet flannel to the back of your neck will keep you cool, or you could consider sprinkling some water onto your clothes so they are slightly damp
  • Avoid dehydration by drinking plenty of water! And not just when you’re thirsty, as this is a sign that you are already dehydrated. Drinking little and often is important, so if you are out and about, make sure to take a litre bottle of water with you and drink throughout the day. If your urine is clear and slightly yellow, this is a sign you are well hydrated
  • Replace electrolytes. This can be a preventative measure as well as a way to treat heat exhaustion. This doesn’t need to be done as frequently as drinking water, but at least once a day during hot weather you should have some fruit juice, coconut water, or Balance Mineral Drink to top up those essential electrolytes.

Cool down with homemade ice cream!

This banana and pistachio 'nice' cream is vegan, easy to make and perfect for warm summer days.

Get the recipe

What we recommend

Try Balance Mineral drink to restore minerals, reduce fatigue and rehydrate after a day in the sun.

Learn more

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