Organisers say they are taking a number of precautions to protect athletes from extreme heat. Outdoor endurance events such as the marathon and triathlon will start early, at 8am, when it is cooler, and athletes will have access to water stations and shaded areas at regular intervals, says Lambis Konstantinidis, executive director of planning and coordination at the Paris Olympics. The triathlon will be postponed if the temperature rises above 32.2C (90F), Konstantinidis says.
The AC question
In a bid to halve the carbon footprint of the Paris Olympics compared with previous games, air conditioning units have not been installed in the Olympic Village.
Instead, the village will be cooled by a geothermal system which pumps water from deep below the ground to keep indoor temperatures 6C (10.8F) lower than outside, according to the organising committee. More than 9,000 trees have also been planted in the Olympic and Paralympic villages to provide natural cooling. The "natural freshness" of the River Seine will also help cool the city centre, says Konstantinidis.