I've been cold in an office at work and ran a stress test on an old laptop which was destined for e-recycling, so that it would blow warm air on my hands.

It wasn't achieving anything doing that work, but it did work well. At least I think the office was cold from not being heated enough, as opposed to being over-cooled in summer. I really hope that was the case!

For some reason, I must have been using the laptop for another purpose too, and I got attached to it and requested that it be wiped and took it home and used it as a daily-driver for years. It was a silly blue Dell E4300, and had a very easily swappable HDD tray so I bought a few different trays/faceplates, and could dual-boot by swapping HDDs in seconds (it didn't really need the screw to hold the tray in place). Bad battery life, but the battery could be swapped in seconds too.

https://www.notebookcheck.net/Dell-Latitude-E4300.12612.0.ht...

The alt-text on this one is particularly relevant: https://xkcd.com/1172/