I've found that if i let my antminer get to 10 Celsius(on board reading) while mining, it has a tendency to constantly reboot. If I use a IR thermometer it usually reads -20 C. I think the super low temperature could be doing funny things with the electrolyte in the capacitors. So now I have it in a container that has a small vent, inside the box while mining it's usually around 10 C and the miner itself reads 35-40 while the IR shows 0-10C on the caps themselves. Could also be the PSU since it's in the same box...But anyways that's been my experience with mining in the frigid north.