A surge of extreme heat is sweeping across the UK this week. For only the second time in history, a Met Office red warning for extreme heat has been issued for parts of England and Wales. With temperatures soaring towards 40C, it is crucial to understand the distinction between heat exhaustion and heatstroke.
The risks are serious. On Wednesday, the London Ambulance Service recorded its highest-ever number of life-threatening emergencies, which was driven by the extreme heat, according to reports. Recognising the warning signs and distinctions between these conditions is a key part of staying safe.
Difference between heat exhaustion and heatstroke
Both conditions are forms of heat illness. At the most severe end of the scale is heatstroke, as it can be life-threatening. Everyone faces the risk of heat illness during hot weather, but certain groups are particularly vulnerable, including older people, babies, young children, and people with long-term health conditions like diabetes or heart problems.
What is heatstroke?
Heatstroke occurs when heat overwhelms the body's capacity to regulate its temperature, leading to reduced blood flow and damage to vital organs. The NHS advises anyone experiencing symptoms of heatstroke to seek urgent medical attention. Heatstroke symptoms can include a high body temperature or fever, usually more than 40C, fainting or losing consciousness, a seizure or fit, severe difficulty breathing (for example, struggling to speak without pausing, gasping, or choking), confusion, lack of coordination, and skin that is cold to the touch, even with a high body temperature.
What is heat exhaustion?
Heat exhaustion occurs when the body overheats, essentially when it loses excessive quantities of water and salt, typically through perspiration. Fatigue, muscle cramps, and heat rash are among the warning signs of the condition. The symptoms are generally identical in children and adults, although children may additionally display unusual behaviour. NHS Inform has outlined the following symptoms of heat exhaustion: tiredness, weakness, feeling faint, headache, muscle cramps, feeling or being sick, heavy sweating, feeling very thirsty, and heat rash.
