The health risks of a heatwave Temperatures in the Greek heatwave are reaching 45C. BBC News Online examines what can happen when the body gets too hot. Prolonged exposure to high temperatures can lead to heat exhaustion and eventually to heatstroke.
Vulnerable people can begin to suffer problems when the temperature rises into the thirties.
By the time the thermometer tops 40C, everybody is potentially at risk. Heat exhaustion refers to overheating of the body due to excessive loss of water or, in rare cases, salt depletion. People who suffer from heat exhaustion have often been taking part in strenuous physical exercise. Symptoms include thirst, headache, pallor, dizziness and possibly nausea or vomiting. In severe cases, the heart may race and the sufferer may feel disoriented.