Does heat exhaustion cause excessive thirst?

Heat and physical effort increase sweating. As water and salts leave the body, the brain signals thirst and you may notice a dry mouth, tiredness, weakness, dizziness or a fast pulse. Thirst can occur before you recognise other signs of heat illness. It can also have causes unrelated to heat, so thirst alone does not identify the cause.

Stop exertion and move to a cool, shaded or air-conditioned place. Loosen extra clothing and cool the skin with damp cloths or a fan. If you are awake and able to swallow, take frequent small sips of cool water or an oral rehydration drink. Avoid alcohol and strenuous activity while recovering. Do not force fluids if vomiting, confused or drowsy.

Seek urgent help if the person becomes confused, faints, has a seizure, cannot drink, keeps vomiting, develops very hot skin, or does not improve after moving to a cool place and resting. These signs can indicate a more serious heat illness. Arrange medical assessment if thirst continues after cooling and drinking, or if urination becomes markedly reduced.

Ask whether your symptoms fit heat exhaustion, how to replace fluids safely, and whether medicines or another condition could be contributing to persistent thirst.