When to worry about excessive thirst with heat exhaustion

Heat exhaustion follows loss of water and salts through sweating, often during hot weather or exertion. Thirst may occur with heavy sweating, weakness, headache, nausea, dizziness, cool clammy skin, or muscle cramps. Symptoms should be taken seriously because heat illness can progress if the body cannot cool itself.

Risk is higher when someone works or exercises in heat, has recently been ill, or takes medicines that affect sweating or fluid balance. Older adults and children may need help recognising or reporting symptoms.

Stop activity, move into shade or an air-conditioned place, loosen excess clothing, and cool the skin with wet cloths or a fan. If the person is awake and able to swallow, offer cool water or a suitable rehydration drink in small sips. Stay with them and watch whether alertness, nausea, dizziness, and sweating improve.

Call emergency services for confusion, unusual behaviour, collapse, seizure, loss of consciousness, severe breathlessness, or very hot skin. Get urgent help if the person cannot drink, keeps vomiting, has worsening symptoms, or does not improve promptly after cooling. Do not give fluids to someone who is unconscious or struggling to swallow.

Ask what caused the episode, how to pace activity in heat, and whether any medicine or health condition changes your fluid plan. Discuss warning signs that should end exercise or outdoor work, and how to prevent a repeat episode.