For me the hardest part is sleeping. I can cope with heat during the day, but even with good bedding, mattress, windows open, fans, etc. the body traps heat underneath and if it's hot outside it's just impossible to sleep. I was like a zombie for 2 months this year. And sleep deprivation in general has a ton of adverse health effects.

Unfortunately, I do live in a "heritage" building so split unit is a no-no. Midea pre-filled mini-splits went from €700 to 2000-3000+ and months of lead time. It's crazy.