Your best bet is to get your own enclosure ASAP. And then begin a strict quarantine process.
Forget EVERYTHING your roommate has told you. Just because somebody kept an animal in the past doesn't mean they kept it in a healthy situation or kept it properly. Unfortunately, your roommate clearly doesn't understand the biology of snakes or the importance of keeping the animal safe.
But getting your own enclosure, heating equipment and thermostat should be your top priority.
If you're not familiar with quarantine you'll want to read up on it and follow it VERY strictly. You'll need all your own water dishes, substrate, feeding tongs, decor, etc...etc...etc...
Feel free to ask any questions you may have, we're happy to help.