we use Air conditioner for hot as well, 17 degrees is still cold for my body
We use electric ovens for heat. Some use fireplaces, which of course I cannot do. Air conditioners are for cooling. I don't have one at home, but I do at work. Feels refreshing when things get too hot. No chance of that in this season, though.
When we're up to 17 degrees my outdoor outfit is shorts and a T-shirt. Something like what the players are wearing now at the AO - when playing.