Cooling of electronic components
"A bit warm" is not a very useful design criteria (unless you are in biological markets, where this can be an issue).

Too hot to handle can be as little as 45°C, which would barely register for most electronics. Burnt skin starts at around 60°C which is at the low-end temperature of many CPUs in modern computers. Design operational temperatures for power electronics can exceed 100°C.

Higher temperatures do affect lifetimes, but the effect is exponential, so not too much of an issue at the lower end of the range.

"A bit warm" is fine for most designs.