It sure seems like you are all in the dark, no not a light switch, I have a window just above my desk.  Not a heater, although the central heating switch is on the wall next to me.

Honestly it is so blatently obvious.  Think! Go through the process yourself.  You come down the stairs and enter your den which is lit and warm, your camera is in the corner, you pull out your chair and sit.  What is the first thing you do??????