<p>Maybe the roomie just said it in passing. Maybe he said it as a way of signalling that he was hoping to keep the heat costs down. Of course, it would be preferable for him to just address the issue directly, but lots of kids–and older people! 
--do not have the skills to discuss/negotiate something like this in a way that doesn’t provoke hostility. Ultimately, he is responsible for half the electric bill, no matter what. </p>
<p>Did both of them sign the lease? Together or separately? Some electric utilities have plans where you can pay a set amount every month to stretch out the high winter costs and budget. But even then, there is a reading at the end of the year and there will be additional charges if it is over a certain threshold.</p>