User menu

Heatwave Advice

With the high temperatures we are experiencing, it’s important to keep an eye out for signs of heat exhaustion, heatstroke and dehydration.

Heat exhaustion and heatstroke are two potentially serious conditions that can occur if you get too hot.

They usually happen during a heatwave or in a hot climate, but can also occur when you’re doing very strenuous physical exercise.

  • Heat exhaustion is where you become very hot and start to lose water or salt from your body, which leads to the symptoms listed below and generally feeling unwell.
  • Heatstroke is where the body is no longer able to cool itself and a person’s body temperature becomes dangerously high (sunstroke is when this is caused by prolonged exposure to direct sunlight).

Heatstroke is less common, but more serious. It can put a strain on the brain, heart, lungs, liver and kidneys, and can be life-threatening.

If heat exhaustion isn’t spotted and treated early on, there’s a risk it could lead to heatstroke.

Signs of heat exhaustion can include:

  • tiredness and weakness
  • feeling faint or dizzy
  • a decrease in blood pressure
  • a headache
  • muscle cramps
  • feeling and being sick
  • heavy sweating
  • intense thirst
  • a fast pulse
  • urinating less often and having much darker urine than usual

What to do

If you notice that someone has signs of heat exhaustion, you should:

  • get them to lie down in a cool place – such as a room with air conditioning or somewhere in the shade
  • remove any unnecessary clothing to expose as much of their skin as possible
  • cool their skin –use whatever you have available, such as a cool, wet sponge or flannel, cold packs around the neck and armpits, or wrap them in a cool, wet sheet
  • fan their skin while it’s moist – this will help the water to evaporate, which will help their skin cool down
  • get them to drink fluids – this should ideally be water, fruit juice or a rehydration drink, such as a sports drink

Stay with the person until they’re feeling better. Most people should start to recover within 30 minutes.

If the person is unconscious, you should follow the steps above and place the person in the recovery position until help arrives (see below). If they have a seizure, move nearby objects out of the way to prevent injury.

When to get medical help

Severe heat exhaustion or heatstroke requires hospital treatment.

You should call 999 for an ambulance if:

  • the person doesn’t respond to the above treatment within 30 minutes
  • the person has severe symptoms, such as a loss of consciousness, confusion or seizures

How to prevent heat exhaustion and heatstroke

 

Stay out of the heat

  • Keep out of the sun between 11am and 3pm.
  • If you have to go out in the heat, walk in the shade, apply sunscreen and wear a hat and light scarf.
  • Avoid extreme physical exertion.
  • Wear light, loose-fitting cotton clothes.

If you’re travelling to a hot country, be particularly careful for at least the first few days, until you get used to the temperature.

Cool yourself down

  • Have plenty of cold drinks, and avoid excess alcohol, caffeine and hot drinks.
  • Eat cold foods, particularly salads and fruit with a high water content.
  • Take a cool shower or bath.
  • Sprinkle water over your skin or clothing, or keep a damp cloth on the back of your neck.

If you’re not urinating frequently or your urine is dark, it’s a sign that you’re becoming dehydrated and need to drink more.

Keep your environment cool

  • Keep windows and curtains that are exposed to the sun closed during the day, but open windows at night when the temperature has dropped.
  • If possible, move into a cooler room, especially for sleeping.
  • Electric fans may provide some relief.
  • Turn off non-essential lights and electrical equipment, as they generate heat.
  • Keep indoor plants and bowls of water in the house, as these can cool the air.

 

 

Dehydration occurs when your body loses more fluid than you take in.

 

Some of the early warning signs of dehydration include:

  • feeling thirsty and lightheaded
  • a dry mouth
  • tiredness
  • having dark coloured, strong-smelling urine
  • passing urine less often than usual

Who is at risk from dehydration?

Anyone can become dehydrated, but certain groups are particularly at risk. These include:

  • babies and infants – they have a low body weight and are sensitive to even small amounts of fluid loss
  • older people – they may be less aware that they are becoming dehydrated and need to keep drinking fluids
  • people with a long-term health condition – such as diabetes or alcoholism
  • athletes – they can lose a large amount of body fluid through sweat when exercising for long periods

What to do

If you’re dehydrated, drink plenty of fluids such as water, diluted squash or fruit juice. These are much more effective than large amounts of tea or coffee. Fizzy drinks may contain more sugar than you need and may be harder to take in large amounts.

If you’re finding it difficult to keep water down because you’re vomiting, try drinking small amounts more frequently.

Infants and small children who are dehydrated shouldn’t be given large amounts of water alone as the main replacement fluid. This is because it can dilute the already low level of minerals in their body too much and lead to other problems.

Instead, they should be given diluted squash or a rehydration solution (available from pharmacies). You might find a teaspoon or syringe can be helpful for getting fluid into a young child.

If left untreated, severe dehydration can be serious and cause fits (seizures), brain damage and death.

When to see your GP

See your GP if your symptoms continue, despite drinking plenty of fluids, or if you think your baby or toddler is dehydrated.

If your GP suspects dehydration, you may have a blood test or a urine test to check the balance of salts (sodium and potassium) in your body.

Contact your GP, out-of-hours service or NHS Direct Wales on 0845 46 47 straight away if you have any of the following symptoms:

  • extreme thirst
  • feeling unusually tired (lethargic) or confused
  • not passing urine for eight hours
  • rapid heartbeat
  • dizziness when you stand up that doesn’t go away after a few seconds

You should also contact your GP if your baby has had six or more episodes of diarrhoea in the past 24 hours, or if they have vomited three times or more in the past 24 hours.
Please visit NHS Direct Wales for more information on dealing with and avoiding heat exhaustion, heat stroke and dehydration.