Is Britain now hotter than ever? Alex Beresford examines the science and the history of our weather to find out. Alex learns about the dangers of heatwaves, when extreme hot weather can shut down transport, damage crops and give people heat exhaustion. He experiences the dangers of rising temperatures when he endures a simulated heatwave. The programme examines the severe heatwave of 2003, which killed around 2000 people in Britain, when temperatures hit 100 degrees Fahrenheit in the South East. Alex also examines the famous heatwave of 1976, when two months of prolonged warm temperatures caused a severe drought, and the Edwardian heatwave of 1911, which lasted nearly three months. The Earth's position relative to the sun also makes temperatures go up or down. Alex investigates how the planet's alignment changes over time in a series of orbital cycles called Milankovitch Cycles. When the cycles align the planet can be plunged into an ice age; another one should arrive in around 1500 years. But right now, a different factor is affecting our temperatures: CO2 emissions. Could hot deadly summers like 2003 soon become the norm in Britain?