If you’re checking for heatstroke symptoms, focus first on the person’s thinking and coordination—not whether their skin is dry. Confusion, collapse, a seizure or loss of consciousness in someone exposed to heat is an emergency. Call for an ambulance and start cooling them straight away; don’t wait for a thermometer or for sweating to stop.
Heatstroke Symptoms And Heat Exhaustion Symptoms
Heat exhaustion commonly causes weakness or tiredness, dizziness, headache, nausea, cramps, intense thirst and heavy sweating. Skin may be pale and clammy, and the person is usually still alert and able to respond normally. They need to get out of the heat, cool down and drink if they can do so safely.
Heatstroke is more dangerous because the body’s temperature regulation is failing and the brain may be affected. Warning signs include confusion, unusual or agitated behaviour, poor coordination, slurred speech, seizure or collapse. The skin may be very hot, and breathing or heartbeat may be rapid. A measured core temperature above 40°C (104°F) is associated with heatstroke, but don’t delay action to get a reading.
The symptoms can overlap, and you may not be able to tell the two conditions apart confidently. A new change in mental state is a particularly serious warning sign. If the person is confused, collapses, has a seizure or becomes unconscious, treat it as suspected heatstroke and call emergency services.
Why Sweating Does Not Rule Out Heatstroke
Hot, dry skin is a recognized heatstroke sign, but it isn’t present in every case. People with exertional heatstroke—after strenuous activity in the heat—may still be sweating. So can someone in the early stages of a serious heat illness. Sweating alone cannot tell you whether a person is safe. Look at the whole picture, especially alertness, speech and coordination.
Heatstroke can happen during exercise or hard physical work, but it can also develop without exertion during prolonged exposure to heat. It can cause serious organ damage and may be fatal without urgent treatment. That is why suspected heatstroke needs emergency help even if the person is still sweating or no temperature has been taken.
What To Do While Emergency Help Is Coming
- Call your local emergency number. Use 911 in the United States, 999 or 112 in the United Kingdom, 112 in many EU countries, or 000 in Australia. Put the call on speaker if possible so you can follow the dispatcher’s instructions while helping.
- Move the person somewhere cooler—into shade or an air-conditioned space—and remove unnecessary outer clothing. Stay with them.
- Start cooling immediately. Wet their skin with cool water and fan them, or use a cool, wet sheet or towels. Keep refreshing the water and airflow. If they are conscious and it is safe to do so, a cool shower or immersion in cool water may help cool them quickly. Don’t leave them alone in water.
- Do not give drinks to someone who is confused, very drowsy, having a seizure or unconscious. If they are fully alert and can swallow normally, small sips of cool fluid may be appropriate while help is on the way. If they become unconscious but are breathing, place them on their side and follow the dispatcher’s advice.
Cold-water immersion is considered the fastest cooling method in clinical care, particularly for exertional heatstroke. It may not be practical or safe to arrange in an emergency without help. Wetting the skin and adding airflow, or using cool wet coverings, are practical alternatives. Cold packs can be an extra measure, but don’t let finding them delay cooling. For more on airflow in hot conditions, read when a fan helps—and its limits.
When Heat Exhaustion Also Needs Urgent Help
For suspected heat exhaustion, move the person to a cool place, remove excess clothing, cool their skin and offer water or an oral rehydration drink only if they are fully alert and able to drink. Stay with them and watch for any change in their condition. If they are getting worse, cannot drink, feel faint or become confused, seek urgent medical help; confusion, collapse or seizures call for emergency services rather than waiting to see if rest works.
Emergency guidance varies by location. In England, NHS guidance advises calling 999 for heatstroke signs and using NHS 111 for heat-exhaustion advice when needed; it notes that uncomplicated heat exhaustion should begin improving within 30 minutes of cooling and fluids. That 30-minute window is not a reason to wait when someone is confused, collapsing or having a seizure. Elsewhere, call your local emergency number for suspected heatstroke. A clinician should assess anyone with concerning or persistent symptoms.
