I will wait until the indoor temperature is below 7c before considering heating, and if the wife complains I throw her a couple of blankets. Of course I don't wear clothes but have to remember to pop on a dressing gown when the doorbell goes for fear of scaring the postman. Outside I will wear my speedos and will wear only these providing the temperature doesn't drop below 0c. It plays havoc with me bunions though so I try to put some slippers on.
In summer I've been known to tolerate temps up to 45c but some people can make my blood boil and that of course is what tips me over the edge leading to my needing a cold shower. Especially her next door but one who is constantly running her aircon which right gets on my wick as it's not necessary.
When I were a lad we didn't have heating or aircon. We sat round a single candle or all shared a very cold bath. All 12 of us.