As the #heatwave warnings are spreading across Europe, may be the "how does furries cope with wearing full body costumes even when it is warm?" question again deserve some attention.
We do not have "superpowers", we have a "secret", a while back, a furry started to make cooling vests to wear under the suits.
The cooling elements used keep a pretty constant, "cool" temperature for hours, warm enough that you will not hurt yourself by having the element on your body for a long time. The warmest element keeps is 21c, and while that does not sound like cooling a lot, 21c is a LOT cooler than 40c.
These things prevent us from over heating while in suit, something that can be quite dangerous. You do not need to be a furry to buy them though.
The vests cost a lot, but even "spare inserts" for cooling collars helps a LOT, but if you go for a "smaller" solution, 15c elements might be better.
I am not affiliated, but have used their products for years, it durable and high quality.
https://www.ezcooldown.com