[tomschlick]

> in their peak can't handle 26 Celsius

Why would any athlete or group want to risk the chance of not being able to sleep well if they are too hot.

[acdha]

26°C isn’t even 80°F. Unless they’re used to training all winter in Fairbanks, it seems like an exaggeration.

[toss1]

It is no exaggeration. Different people have different sleep requirements.

Your "26°C/79°F" is also only the normal case. It fails to account for how the system will perform in the now far more common 'outlier' heat waves that occur in Europe.

It also fails to account for the occasional requirement to cool down between events. Some athletes have multiple events on the same day, such as series of qualification rounds. Having competed at up to international levels and a variety of sports, I've it was a significant advantage between events or before events in hot conditions to taking a cold shower and rest and mentally prep in a very cool room before the event. 79°F does not cut it. I'd need more like 59°F. It's only for an hour or so, but it makes a huge difference to show up at the event on a blazing day with my core body temp still cool and not even wanting to sweat yet. It got hot enough in a few minutes, but being able to blast the AC for an hour definitely helped.

Before posting you might consider either getting serious direct experience or at least real information about the topic (or instead asking a question vs. making ignorant statements that cast implied insults at people who actually have a clue about their requirements).

[Atreiden]

Some people (myself included) genuinely get garbage quality sleep if it's over 70F or so

[tomschlick]

Some like it colder when they sleep. For instance I tend to keep mine at 69-71F depending on the time of year at night on my upstairs climate zone.