He is breaking the law!

Tell the landlord he is breaking the law. I don't know which state you are living in now, but here in New York the law requires that the lanlord maintain the tenant's room temprature at 68 C or the tenant is entitled not to pay the rent.

if the landlord listens to you and let you use the heat, but later he finds out some excuse and tries to terminate the rental agreement, the law presumes it a retaliatory eviction if he does so within 6 months from when the tenant brings the matter to the court.

So don't be upset, fight for your rights.

Good luck!