Heater not working

It was freezing cold in the middle of the night. I was not surprised as the weather is getting colder day after day. When I woke up, I sat down and light up a cigarette. I could not feel the warmth from the heater. I went out and check other heaters and yes they are working. Then I checked the heater's temperature, a smart housemate turned it to 30C. No wonder the heating is not working.

Now, my room's heater is not working again. I guess, I will spend my night at my friend's room.