When it's damn too hot.
Seconded. Heat would be my answer. Anything above 86°F/30°C is irritating. Anything above 95°F/35°C gives me a continual, burning passionate hatred for life itself. With the cold, at least you can layer up and do something about it. With the heat, you're just helpless, powerless to prevent your fate of suffering every second of your exposure to it.
Well said! I was in Orlando in August, and it was in the low to mid 30's Celsius, and it made me wonder how people could live with that on a regular basis. Doing outdoor labour in the south must be terrible!
Then again, my younger brother is moving to Thompson, MB for work. If I lived up there during the winter, it would make me realize how crappy
true cold is.