2 Watson vs Nicklaus: The famous "Duel in the Sun" took place at Turnberry in 1977.
3 Badwater Ultramarathon: A race in California's Death Valley where temperatures reach 49C.
4 USA World Cup 1994: Jack Charlton was reprimanded for throwing water bottles to his Ireland players to cool them down against Mexico.
5 Tommy Simpson: The British cyclist died due to extreme heat in the 1967 Tour de France.
6 Scottsdale Beat the Heat Race: Held in Arizona in June, it is designed to make competitors "uncomfortable".
7 Fire-fighting Sports: Developed in the Soviet Union in the 1930s.
8 Paris Dakar Rally: The punishing off-road race was held in the desert heat of Africa.
9 Knud Jensen: Danish cyclist who died of heat stroke in the 1960 Rome Olympics.
10 2022 Qatar World Cup: It might have to be held in winter because of the heat.