I think it has to do with the fact that we are 98° because we create that heat as a by product of living, and there has to be a way for that created heat to be released and moderated.
The hotter it is outside, the harder it is to keep your body cool and prevent overheating. When it's cold, your body has to make more heat energy to keep itself from freezing or slowing down so much you can't operate.
For some reason, sleep mode doesn't even work on my laptop cause it'll never resume, it seems to treat any call to sleep as a call to shutdown. I've always had to just save my work and poweroff if i was going anywhere without a charger. I had a little bit of luck with TLP until I had a microcode update and that somehow broke it even worse.