IIRC they said it used liquid cooling. I’m NOT a fan of that. They DID say the two new Lumia phones use liquid cooling.
How the heck is that done?
It’s internal liquid cooling I’m sure. It probably has a system that pumps the liquid over the CPU/GPU and then moves it to the cooler locations of the phone. If you ever used a Nokia 920 you know they needed to find a better cooling solution...those things get HOT. Liquid cooling in a phone makes a lot of sense to me.
Probably a heat pipe / convective circulation type thing.