As Brits face a record-breaking heatwave this Bank Holiday weekend, health experts are warning people not to ignore one surprising symptom of heat exhaustion. Forecasters say temperatures across parts of the UK could break the 32.8C record in May over the long weekend, with soaring heat increasing the risk of dehydration, heat exhaustion and potentially deadly heatstroke.

Data from the UK Health Security Agency shows there were an estimated 1,504 heat-associated deaths in England during the summer of 2025 across five separate heatwaves. The NHS says heat exhaustion does not usually require emergency medical treatment if the person can cool down within 30 minutes. However, if symptoms worsen or develop into heatstroke, it becomes a medical emergency.

According to the NHS, heat exhaustion occurs when the body becomes too hot and struggles to cool itself down properly. While many people recognise symptoms such as dizziness or excessive sweating, one symptom is often overlooked despite being one of the key early warning signs.

That symptom includes painful cramps in the arms, legs and stomach. They can occur during heat exhaustion because the body loses large amounts of water and essential salts, such as sodium and potassium, through excessive sweating. These electrolytes help muscles function properly, and when levels drop, muscles can begin to spasm or cramp painfully. Hot weather, dehydration and physical activity can all increase the risk, particularly during heatwaves when the body is working harder to stay cool.

Experts advise anyone experiencing heat cramps to stop physical activity immediately, move to a cool place and drink fluids such as water or rehydration drinks. Stretching and gently massaging affected muscles may also help ease discomfort.

Other symptoms of heat exhaustion include tiredness, headaches, nausea, weakness, fast breathing, a high temperature and feeling extremely thirsty. The NHS also warns that skin may become pale and clammy or develop a heat rash, although changes in skin colour can be harder to identify on brown and black skin. Children may also become unusually irritable.

Anyone suffering from heat exhaustion should be moved to a cool place, given fluids such as water or sports drinks and helped to cool down with damp cloths, cool water sprays or cold packs placed under the arms or around the neck.

Most people should begin to recover within half an hour. If symptoms continue, people are advised to contact NHS 111 for further advice.

The NHS warns that heatstroke can develop if heat exhaustion is left untreated. Signs of heatstroke include confusion, seizures, loss of consciousness, a very high temperature and hot skin that is no longer sweating. In these cases, people should call 999 immediately.