Mårtensson is in Paris to help the Swedish Olympic Committee with weather forecasts during the Olympic Games.
Today is the warmest day and already 31 degrees at the Eiffel Tower, seven degrees warmer than at the same time yesterday, says Mårtensson at lunchtime.
It can reach 36-37 degrees over the Paris area today.
One who competed in the heat is dressage rider Juliette Ramel.
It's very hot, you mostly think about the horses not getting too hot, that they don't get overheated. But he handled it well, she says about Buriel.
Not suffering in advance
After her performance, the horse was cooled down with ice water and Buriel's temperature was taken.
I've drunk a lot. You know it's going to be very hot and you don't suffer from it in advance.
Later tonight, rain showers, locally up to 35 millimeters, are expected to move in over the Olympic city, along with thunder and strong winds. But then all Swedish outdoor athletes – in dressage, canoe slalom, shooting, and sailing – will have finished competing. However, the bad weather, and especially the thunder, can cause problems for example for beach volleyball in the evening.
Will get cooler
By Wednesday's competitions, the bad weather will have passed, but local showers may occur and it will remain hot for a couple of days.
On Friday, cooler air from the Atlantic will blow in and it will drop to 25 degrees at least, more of a Scandinavian feel, says Mårtensson.
Then it will be easier for the body's load.
Before the Olympic Games in Tokyo 2021, the Swedish Olympic Committee made an effort to prepare the Swedish Olympic participants for heat and high humidity.
We've reused that concept now since we knew it could be days like today. Many are used to the heat, but there are those who aren't, says Mårtensson.