Only providing a possible physical explanation. My bias is to look for things like that when I see or hear about things I can't explain.
My search-fu seems to be broken, so I'm sorry if this is repetitive (or if it's not the same version I told before several years ago. I haven't thought about it recently so [link|http://www.newscientist.com/channel/being-human/mg19325961.400-future-recall-your-mind-can-slip-through-time.html|this version may be different]).
Once in late winter I was in a class in an old building. The steam heat was on full blast and the windows were open. It was a boring lecture, so I was daydreaming. Late afternoon light was streaming through the window. When I looked straight ahead, everything looked normal. But there was a guy sitting in a desk in the sunlight and he looked like he was on fire when seen with my peripheral vision! I looked at him directly and didn't see the effect. It was only when I used my peripheral vision.
The heat rising from the hot radiators explains the shimmering, but what about the red color? It wasn't simply the sunlight - the light wasn't the same color.
I told a friend about it and he said he thought it was an illusion that was an artifact of our peripheral vision having [link|http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html|different color sensitivity] than the center of our visual field.
If I were a superstitious person, I would have thought that I was seeing his future or something. I don't believe that. :-)
Obviously, I wasn't there - I don't know what was going on in your house. I do know that [link|http://en.wikipedia.org/wiki/Newton's_Laws|Newton's Laws] have worked pretty well for explaining physical phenomena for several hundred years so I'm not willing to give them up without a fight.