I have never understood this! My office has no AC and a window to the south. Temperature is 31C right now and probably will be 35C in the afternoon and I love it! :) 28C is barely OK and below 25C I will go and fetch a sweater. 20C is freezing cold.

I hope this does not mean that my hardware is suffering too much, though! I do underclock everything (Laptops) to around 700MHz, but still... looks like I'll stick to the Raspi 3 for now.