Heat exhaustion and shaking: what to know

Muscle trembling can accompany heat exhaustion when the body is strained by heat, sweating, dehydration, fatigue, or changes in fluid balance. It may occur with weakness, dizziness, nausea, headache, thirst, or cramps. Shaking after moving into a cool environment can also be a response to rapid cooling. The symptom alone cannot distinguish heat exhaustion from low blood sugar, medication effects, infection, anxiety, or heatstroke, so the person’s alertness and overall condition matter.

Stop exertion and move to shade or air conditioning. Remove excess layers, cool the skin gently with damp cloths and airflow, and rest. If fully awake and swallowing normally, take small sips of water or an oral rehydration drink. Do not force fluids, give food or drink to a confused person, or use ice directly on the skin. A companion should stay nearby and observe whether shaking and other symptoms settle as the person cools.

Call emergency services for confusion, unusual behaviour, fainting, seizure, severe weakness, breathing difficulty, chest pain, or inability to drink. Seek urgent advice if shaking continues, intensifies, or occurs with persistent vomiting, severe headache, very hot skin, or reduced urine. Do not assume that sweating or trembling rules out a dangerous heat illness.

Ask whether dehydration, a medicine, low blood sugar, or another condition could have contributed, how to prevent recurrence, and when it is safe to return to heat or exercise.