The cooling break was introduced by FIFA in 2014. Here's a reminder of how it works in Ligue 1 Uber Eats.
What is a cooling break? When the temperature is at least 32 degrees during a match, the referee applies the 'cooling break': a match interruption intended for the hydration of the players. Typically, these breaks take place around the 25th minute of the first half and around the 70th minute of the match. When playing conditions call for a cooling break, the referee communicates this to both teams before kick-off.
The duration of the break is limited to two minutes between the stoppage by the referee and the official resumption of the match. The referees, like the match timer, refrain from stopping the timing of the break. This specific two-minute stoppage time is added to additional time at the end of each half. If the weather gets better in the second half, the referee, with the agreement of both teams, may refrain from taking another break.