Heatstroke: the warning signs and what to do
Heatstroke is recognised by a body temperature above forty degrees together with an altered mental state, and it is a life threatening emergency requiring a call to 112 and immediate active cooling of the person.
gelisted editorial team · Updated 15 August 2026
The short version
- The reference temperature for heatstroke is above 40 degrees.
- Confusion or loss of consciousness distinguishes it from heat exhaustion.
- Cooling must begin before help arrives.
- The highest risk hours run from 12 to 17.
There are two distinct conditions and they are easily confused. One resolves in the shade with water; the other can be fatal within the hour.
Heat exhaustion and heatstroke
In heat exhaustion the person sweats heavily, the skin is cool and damp, and there is weakness, nausea, cramps and dizziness, but mental state is intact. In heatstroke the temperature exceeds 40 degrees, the skin may be hot and dry, and confusion, strange behaviour, seizure or loss of consciousness appear. That change in mental state is the sign that separates one from the other.
| Sign | Heat exhaustion | Heatstroke |
|---|---|---|
| Temperature | below 40 °C | above 40 °C |
| Mental state | intact | altered |
| Sweating | heavy | may be absent |
| Skin | cool and damp | hot |
| Action | shade, water, rest | call 112 and cool |
| Expected improvement | 30 to 60 minutes | hospital required |
| Risk to life | low | high |
The first minutes
Call 112. Move the person to a cool, shaded place. Remove excess clothing. Cool actively: cold water over the skin, damp cloths, ice wrapped in cloth at the armpits, groin and neck, and moving air. If conscious and able to swallow, offer small amounts of fluid. If unconscious, give nothing by mouth and place them in the recovery position.
Who is most at risk
People over 65, young children, those with chronic conditions and anyone taking medication affecting thermal regulation or fluid balance. Also those exercising or working outdoors in the middle of the day. On the island, days combining high temperature with high humidity concentrate the risk between 12 and 17 hours.
Humidity matters as much as temperature: when it is high, sweat evaporates poorly and the body loses its main cooling mechanism.
Prevention
Drink regularly without waiting for thirst, roughly a glass every 30 to 45 minutes during outdoor activity. Avoid exposure and effort between 12 and 17. Light, pale, breathable clothing with a hat. Light meals. And check on older people living alone during hot spells with a daily call or visit, which is the single measure that prevents most deaths.
Frequently asked
+How do I recognise heatstroke?
By a temperature above 40 degrees together with confusion, strange behaviour or loss of consciousness.
+What do I do first?
Call 112 and start cooling immediately with shade, cold water, damp cloths and moving air.
+Should I give water?
Only if the person is conscious and can swallow, in small amounts. If unconscious, nothing by mouth.
+Who is most at risk?
People over 65, young children, those with chronic conditions and anyone working outdoors.
+Which hours are most dangerous?
Between 12 and 17, particularly on days combining high temperature with high humidity.
Sources
- 1Ministerio de Sanidad, Gobierno de España (August 2026)
- 2Govern de les Illes Balears, Govern de les Illes Balears (August 2026)