Most of us welcome hot weather, but when it's too hot for too long there are health risks. If a heatwave hits this summer, make sure the hot weather doesn't harm you or anyone you know.
An average temperature of 30°C by day and 15°C overnight would trigger a heatwave health alert (this figure varies slightly around the UK). These temperatures can have a significant effect on people's health if they last for at least two days and the night in between.
Visit the NHS Health Choices website to find out why heatwaves are a problem and who is most at risk.
Visit the Met Office website to find out about the Heat Health Watch Alert service between 1 June and 15 September each year.