If anyone needs a tropical getaway, we live with FIL and he keeps his house a sauna! Year-round, he's in shorts and a t-shirt at home. No joke. It's so hot we had to close our bedroom door, turn off the heat, open the window and consider putting a draft excuder to keep the hot air out. When I'm downstairs cooking or baking, I am sweating if the heat is on.
Annoyingly, he only turns it on when he (or grand-FIL) is home so when no one is home it's ice cold in the dead of winter. Then someone gets home and cranks up the heating. If you didn't hear them arrive, you'd know it because the radiators would be burning hot.
I don't even want to know what his heating bills are.
Before we moved in, I'd adjust the heat based on when I would cook or bake. Double goodness of a toasty flat and fresh bread.