At least 13 people have died in Britain while swimming during a spell of record-breaking hot weather that sparked wildfires, damaged train tracks and triggered warnings that efforts to tackle climate change needed to be stepped up.
The London Fire Brigade endured its busiest day since World War Two on Tuesday when temperatures topped 40C (104 Fahrenheit) for the first time, igniting fires that destroyed dozens of properties in the capital and torched tinderbox-dry grassland at the sides of railway tracks and roads.
