Heatstroke vs Heat Exhaustion: How to Tell the Difference and Act Fast

Queensland is no stranger to extreme heat, and with climate conditions delivering back-to-back record temperature events in recent summers, heat-related illness has become an increasingly visible public health issue. Several heatstroke deaths at outdoor events and worksites were reported across Australia in the 2023–24 summer, yet public understanding of how to respond remains dangerously low. The confusion often centres on a critical distinction: heat exhaustion versus heatstroke.

Heat Exhaustion: The Warning Sign

Heat exhaustion occurs when the body's cooling mechanisms are struggling but still functioning. Signs include heavy sweating, cool and pale or flushed skin, fast and weak pulse, nausea or vomiting, muscle cramps, tiredness and weakness, dizziness, headache, and fainting. The person is usually still conscious and responsive. Treatment: move them to a cool environment immediately, remove excess clothing, apply cool wet cloths or ice packs to the neck, armpits, and groin, have them sip cool water if conscious, and rest lying down with legs elevated. Most people recover well with prompt cooling and hydration.

Heatstroke: A True Medical Emergency

Heatstroke is a life-threatening emergency. It occurs when the body's core temperature rises above 40°C and the cooling system fails. Signs include hot, red, dry or damp skin (sweating may have stopped), rapid and strong pulse, confusion, disorientation, slurred speech, seizures, and loss of consciousness. Unlike heat exhaustion, the person may be irrational or completely unresponsive. Call 000 immediately. Begin aggressive cooling without delay: move them to shade or air conditioning, apply ice or cold water to the neck, armpits, groin, and head, use a fan to accelerate evaporative cooling, and do not give them fluids to drink if unconscious.

Applying DRSABCD to Heat Illness

The DRSABCD action plan applies to any emergency, including heat illness. Check for Danger — remove the person from the heat source. Assess their Response. Send for help (call 000 if heatstroke is suspected). Check the Airway. Check for Breathing. Begin CPR if they are not breathing. Access a Defibrillator if available and indicated. Even if you're unsure whether it's exhaustion or heatstroke, erring on the side of calling 000 is always the right decision when someone is confused or losing consciousness.

Preventing Heat Illness at Queensland Events

Event organisers have specific obligations under Queensland WHS legislation to manage heat risks. This includes providing shade and cool rest areas, ensuring adequate hydration is available, scheduling strenuous activities during cooler parts of the day, training staff to recognise heat illness, and having a clear emergency response plan. Horizon Training can help your organisation prepare for outdoor events with tailored first aid training and emergency planning support.

Sources and further reading

• Heat-related illness — Healthdirect Australia
• Working in heat — WorkSafe Queensland