Calls to London Ambulance Service rise during heatwave
18 July 2013 Last updated at 21:31 BST
The heatwave has caused 999 calls to London Ambulance Service to rapidly rise, with callouts categorised as "life threatening" increasing by 20%.
As the hot weather continues, the service is preparing for a busy weekend.
Claire Stearnes, emergency medical technician and paramedic Sam Martin describe the difficulties the heat presents to them.