Q: What do electronics engineers do when they are asked to reproduce a software bug that crashes the system only after 100 days?
A: Placing it in an oven, heating it up to 125 degrees, and extrapolate the results according to the Arrhenius equation.
The "10-degree hotter, half lifetime" rule in electronics is just the chemical reaction rate in the Arrhenius equation. It's fairly accurate for electrolytic capacitors, but probably not semiconductors. Even in the original 1970s MIL-STD document that made this rule the industry, it acknowledged junction temperate doesn't really matter below a point. It's just that there's really no good way to extrapolate lifetime besides testing it for 20 years, so lacking any alternative, people keep repeating this guideline...
@niconiconi is there an easy to phrase heuristic for the value of the proportionality constant in the exponent?
