Heat stroke: symptoms, prevention and what to do
Heat stroke is the most severe of the heat-related illnesses. It happens when the body can no longer regulate its temperature and it climbs above 40 °C. It is a medical emergency that can damage the brain, heart and kidneys, and can even be fatal if you do not act quickly. Before it reaches that point, heat exhaustion usually appears first, a warning sign that is worth catching early.
On days of extreme heat, the number on the thermometer is not the only thing that matters. Humidity and the feels-like temperature determine how much your body actually suffers. That is why it pays to check the full forecast on Meteo Info Online, with data from Open-Meteo, and to plan your day accordingly.
Heat exhaustion versus heat stroke
Heat exhaustion is the earlier, milder stage. If you recognise it in time, you can stop it from getting worse. Its symptoms include:
- Heavy sweating with cool, clammy skin.
- Weakness, dizziness or fainting.
- Headache, nausea or muscle cramps.
- A fast, weak pulse.
Heat stroke is far more dangerous. A key sign is that the skin is often hot, dry and flushed, because the body has stopped sweating. Other symptoms are:
- A very high body temperature.
- Confusion, agitation or slurred speech.
- Seizures or loss of consciousness.
- Rapid breathing and a racing pulse.
What to do in an emergency
If you suspect heat stroke, call the emergency services right away. While help is on the way:
- Move the person to a cool, shaded place.
- Remove excess clothing and cool the body with water, wet cloths or cold packs on the neck, armpits and groin.
- Fan them to help the moisture evaporate.
- If they are conscious and alert, offer small sips of water. Do not give fluids if they are confused or unconscious.
For heat exhaustion, resting in a cool spot, drinking water and cooling the body is usually enough. If the symptoms do not improve within 30 minutes or get worse, seek medical attention.
The role of humidity and feels-like temperature
The body cools itself mainly through sweat: as it evaporates, it carries heat away. But when the air is very humid, sweat cannot evaporate well and that mechanism fails. This is why a day of 32 °C with high humidity can be more dangerous than 36 °C in dry weather.
The feels-like temperature combines heat and humidity to reflect how hot your body actually perceives the air to be. When this value is high, the risk of heat illness rises even if the thermometer is not at record figures. Always check the feels-like temperature, not just the air temperature.
How to prevent it
Most cases can be avoided with simple precautions:
- Stay hydrated: drink water often, without waiting until you are thirsty. Avoid alcohol and very sugary drinks.
- Avoid the hottest hours: cut back on physical effort between midday and mid-afternoon.
- Find cool places: shade, ventilation or air conditioning.
- Dress appropriately: light, loose, pale-coloured clothing, plus a hat.
- Never leave anyone in a closed vehicle: the interior reaches deadly temperatures within minutes.
Who is most vulnerable
Some people are less able to regulate their temperature and should take extra care:
- Babies, young children and older adults.
- Those with heart disease, diabetes or obesity.
- People taking certain medications.
- Workers and athletes who exert themselves outdoors.
- Anyone not used to the heat during a sudden wave.
Keep an eye on older people who live alone and on young children during intense heat episodes. A little attention and a few simple habits are enough to prevent most heat emergencies.