We keep our house at 22 degrees Celsius (about 72 degrees Fahrenheit) in the fall and winter, but whenever we have certain guests over, they turn the heat up to 26 degrees Celsius (about 80 degrees Fahrenheit) and sometimes higher! We've asked them to please not do this as it runs up our heat bill astronomically, and it makes our house unbearably hot and dry. We've asked that if they're cold, they use the space heater in the guest room.

I feel like it's rude to adjust the thermostat when you're visiting someone, especially if the host has asked you specifically not to do it.