Wuss
I'm a proud fully paid up member of the Wuss club
18/20C is not nice you're being silly
In the same way we tolerate our Summer, where you have a 1 hr boat ride when air temps are 45C+, the top 10-15m of the water 28C then it's 23C . 2 dives plus 60-90 min SI (sweat feast) and 1 hr boat ride home
Heat I can do (you learn to living in the Middle East - Cold, not so much I've just turned the AC off in the house since it's reached a comfortable 26C. People in the UK would claim they were dying if their bedrooms were 26C