Company I worked for. We built an aerial multispectral imaging system for monitoring seals, polar bears, and other mammal populations. It's 3 high power rugged PCs, semi-affixed in a shock mount case in the tail of a Twin Otter. There's no hangars available at the airbases in e.g. Kotzebue, Deadhorse, Utqiagvik, so it sits on the tarmac and experiences some intense temperature swings.

It's made it 2 winters and dozens of missions so far.

The customer is NOAA and they really don't have oodles of cash to spend on this thing, so it's mostly commodity hardware. Initially we designed this whole crazy insulated case to keep it from getting too cold, but the aircraft engineers nixed it due to fire hazards. The airframe isn't airtight so it gets most of the brunt of the diurnal swing.