How to deal with roommates who keep changing the thermostat?

[Anonymous]

I live on campus with two other girls, and in our apartment (aka dorm), we can change the heat/ac settings. So, for the past couple of weeks it’s been in the mid 70’s - low 80’s (Fahrenheit). So I set the thermostat to 70 (AC setting), however, my roommates keep turning the heat up to 75. To me, if it’s hot outside, the heat should not be on. So, we’ve come to agreement to set the heat to 72 (since I bought a fan for my room), but one of my roommates keeps turning the heat up. Any suggestions on what I should do?

[Iron_Man]

Sit them down and have a very serious conversation with them,. It’s April 7 it shouldn’t be that cold now

[Asker]

I did, and we agreed to set the heat (which is still ridiculous) to 72. But one of them keeps turning it up to 75. This morning the heat was on 78... and it was 82 degrees outside

[Iron_Man]

That’s crazy