What should you know about dehydration and heat exhaustion?

Dehydration may cause thirst, a dry mouth, dark urine, headache, tiredness or dizziness. Heat exhaustion adds heavy sweating, weakness, nausea, cool clammy skin and difficulty concentrating after time in a hot environment. Read more about Dehydration and Heat Exhaustion.

Heat exhaustion is different from heatstroke. Confusion, collapse, seizures, loss of consciousness or very hot skin are emergency signs, especially if the person cannot drink safely.

Move to shade or an air-conditioned place, loosen extra clothing and rest. Sip cool water or an oral rehydration drink. A cool, damp cloth or gentle fanning can help lower body temperature. Avoid alcohol and strenuous activity while recovering. Urine that becomes lighter and more frequent can be one sign that hydration is improving.

Call emergency services for confusion, fainting, a seizure, severe breathing trouble, inability to drink, or suspected heatstroke. Seek medical care if vomiting prevents rehydration, dizziness does not settle after cooling and fluids, or symptoms worsen. A clinician can check hydration, temperature and other causes of weakness.

Ask what fluids are suitable, whether medicines or a health condition increase heat risk, and how to plan activity in hot weather. Mention how long symptoms lasted, how much you were sweating, and any vomiting or diarrhoea.