Electronics in cold ambient temperatures
Commercial chips are mostly designed and tested from 0 to 70 C. Industrial chips go to wider ranges, sometimes -40 to +105 C, sometimes more. Military/Aerospace spec are generally qualified from -55 to +125 C and are warehoused in a secure cage separately from commercial and industrial quality chips, with documentation attached to prove their having been tested.
Complete systems are temperature cycled between the limits while cycling the power supply between its limits.
I believe avionics uses mil/aerospace qual chips, therefore should not be a problem at -40.
That's why avionics is so expensive.