What should you know about heat stress heat stroke?

Heat stress happens when the body cannot shed heat effectively, often during exertion or prolonged exposure to a hot environment. Heat exhaustion may cause heavy sweating, weakness, headache, dizziness, nausea, or thirst. Heat stroke is more severe: the brain and other organs begin to malfunction, causing confusion, unusual behaviour, fainting, seizures, or difficulty staying awake. Sweating may continue or may stop, so skin moisture alone cannot rule it out. A high temperature can also occur with infection; see information about Fever if the situation is unclear.

Move the person to shade or air conditioning, remove extra clothing, and cool the skin with wet cloths, fans, or cool water. Stay with them and monitor breathing. If they are confused, drowsy, vomiting, having a seizure, or unable to swallow safely, do not give drinks or medicines by mouth. Do not delay emergency care while trying home cooling. A clinician may use IV Fluid Therapy when fluids cannot be replaced safely by mouth.

Call emergency services immediately for altered awareness, fainting, a seizure, severe weakness, breathing difficulty, repeated vomiting, or suspected heat stroke. Urgent assessment is also needed when symptoms do not improve promptly after moving to a cool place and resting. Do not leave the person alone to travel. Keep cooling measures going while help is on the way.

Ask what likely triggered the episode, whether medicines or a health condition increase heat risk, how to return safely to activity, and which warning signs should prompt immediate review. Mention the person's fluid intake, time in the heat, symptoms, and any first aid already given.