See, that's the benefit of a UK sixties education...
You *know* -40C = -40F without having to think about it, and you can prove it too...
btw: -40C - 85C and only 40G shock loads? I'm working on stuff operating from -40 to +150C, continuous vibration significantly in excess of 40G, and operating pressures around 15,000psi... not as smart as a PC, but if it breaks in service, there's no-one around to fix it.
One of the biggest helps is physically small (= low mass) components.