Interesting observation

I shoot out of my shop quite a bit of the time off a shooting bench. Other day the tempture was in the mid 20's so I turned on my propane unit heater hanging from the ceiling about 30 ft behind me and blows warm air right on my bench mighty, comfy. When I looked throu my scope the heat waves made it impossible. I've looked across a hot desert on a 100 deg day, but this was like that on steroids. Made it impossable to shoot. Another lesson. At least this one was FREE!
 
Now that the weather has significantly dropped here in the PNW I've noticed this when shooting out of my window. 

If I shoot at 8x and under, I don't notice it AT ALL. However when I go anything over 8x I notice it. Also, the closer the target, the less the target moves, but my 95yd target "vibrates" so bad that if I didn't know where it was and what holdover , I'd miss every shot.