1. grow uncomfortably warm because the radiator is fucking ridiculous.
2. crack a window open.
3. get a little chilly.
4. put on a sweater.
5. get still chillier.
6. shut the window.
7. get warm.
8. remove sweater.
9. get still warmer. go back to 1.
and then there's the option of turning the radiator off. which almost makes the room chilly and is kind of a hassle.
my room at uni is exactly like that too. it's a pain in the arse.