Is my crt too close to my heater/window?

I recently read in my Sony Wega KV-32FS120 manual that I should install it away from a heater and window. I don't have much space and this is the best spot for it right now.

Should I put it somewhere else, or is this spot okay? There's around 23 inches between the tv and the heater.

(Sorry for bad crt picture quality)