Heat exhaustion and heat stroke
The summer heat in Aotearoa New Zealand can leave you feeling unwell, even though the climate is generally mild. You might feel heat exhaustion when your body's natural mechanisms are working hard to keep your body temperature stable. Heat stroke is when your body temperature rises too high — it is a dangerous condition.
What heat exhaustion is
Sweating is the body's natural mechanism to cool down, but you can lose significant amounts of fluids and salts (electrolytes) on hot days.
Normally, the body keeps cool by sweating, but when it is very hot and humid, sweating does not work so well. This makes the body work harder to stay cool, which can lead to heat exhaustion.
Signs of heat exhaustion
Heat exhaustion is not usually serious. It occurs after being exposed to heat for a long time.
Signs of heat exhaustion include:
- feeling dizzy or faint
- feeling sick
- heavy sweating
- a fast pulse rate
- having a headache
- having muscle cramps in your arms, legs and stomach.
Treating heat exhaustion
If you have symptoms of heat exhaustion:
- rest in a cool place — lie down with your legs raised
- drink plenty of non-alcoholic, cool drinks
- loosen your clothing — if possible, remove excess clothing
- cool your skin using a shower, if possible, or cover your body with cool, damp towels or sheets.
You should start to feel better within 30 minutes, with no long-term complications. If you do not feel better, go to your healthcare provider or after hours clinic.
General practice and after hours medical care — Healthpoint (external link)
What heat stroke is
Heat stroke is less common but more serious than heat exhaustion.
Heat stroke occurs when your body temperature becomes dangerously high. Your body can no longer cool itself and starts to overheat. This can develop quickly with little warning.
Those more at risk of developing heat stroke include:
- pēpi and tamariki under 2 years
- elderly people
- people with health conditions such as diabetes, kidney, heart or lung problems
- people doing strenuous exercise.
Signs of heat stroke
Signs of heat stroke include:
- hot, flushed (red), dry skin
- confusion
- decreasing consciousness, such as struggling to focus or stay awake
- headache
- dizziness
- feeling sick
- a high temperature (above 40 degrees Celsius)
- a fast pulse rate.
While you are waiting for the ambulance
To help the person, you can:
- move them to a cool area
- remove their outer clothing
- increase ventilation by opening any windows or using a fan
- give them water to drink (if they are conscious)
- cool their skin using a shower, if possible, or cover their body with cool, damp towels or sheets.
If the person becomes unconscious, place them in the recovery position.
How to put an adult in the recovery position — St John Ambulance (UK) (external link)
Preventing heat exhaustion and heat stroke
- Avoid spending too long in a hot environment — stay out of the sun and in the shade.
- Drink plenty of cold, non-alcoholic drinks.
- If you do get hot, have a cool bath or shower.
- Wear a hat and light scarf.
- Avoid strenuous exercise — and if you do exercise, do it in the early morning or evening.
- Wear loose-fitting, cotton clothes.
- Avoid alcohol as it will dehydrate you.
- Keep your house cool — open windows to allow breeze to come through or close up and turn on the air conditioning.
- Never leave tamariki unattended in a parked car.
Look out for your neighbours, especially the elderly, children or people with ongoing health problems — they cope less well with heat. Check they are okay.