Is it okay to use a desk lamp to give my betta’s water a little more heat?

My betta, Rodney, has been alive for almost three years. My dorm room at college this year is a little drafty, and even though Rodney’s tank isn’t near the window, it’s still in the line of the draft. I just felt his water and it was pretty cold.
If I put my desk lamp [...] http://bit.ly/dveuxZ