As Jonny said, for individual parts the best thing is to check their datasheets. However from a general or theoretical point of view, consider the temperature at which silicon ceases to act like a semiconductor. If I remember right from semiconductor devices class many years ago, that is around 150 degC. It would be a good idea to look this up yourself instead of taking my word for it.
Also look at some datasheets for discrete silicon parts. Often they are rated for 150C or thereabouts max die temperature. Keep in mind that is die temperature. Since there is always finite thermal resistance between ambient and the die, the max die temperature is the point at which the device can no longer dissipate any electrical power, making it useless in a practical sense. Something like a mouse doesn't handle much power, so can maybe operate near the theorectical limit.
Then there is another effect. All dies are not created equal, even off the same wafer. Manufacturers test each one and sometimes bin them differently depending on special desirable characteristics they find. The ability to run at high temperature can be one of these characteristics. The dies that can stand high temperature may be sold as extended range parts, which means the non-extended range parts probably do crap out at lower temperature because they were selected that way.
Most silicon semiconductor chips are specified over at least the 0-70 degC ambient range, often with extended temperature range versions available for a higher price. In the case of chips, this is usually the ambient temperature, not the die temperature.
So to sortof answer your question, a unknown electronic device using silicon semiconductors and not specificaly handling power can probably survive 70C ambient. Maybe it can survive 100C ambient. When they dies get to 150C, they very likely won't work. What that means in terms of ambient is somewhat of a guess.