As the original French title helpfully tells us, it's 37°2 in the morning.
Off the scale. In that heat, most folk would steer clear of exercise.
Not raunchy Gallic fuck-buddies Zorg (Jean-Hughes Anglade) and Betty (Beatrice Dalle), intent on soaking their sheets regardless.
How To Cool Down:
Stop having sex. Although, with foxy Dalle gagging for it, that's easier said than done.