Interesting followups, thanks.
When we summited San Jacinto on Jan 17th, we were pretty warm from the steep climb. We had started late so knew we had to get back down pretty quickly. But we stopped for 20 minutes to take pictures, eat some lunch, etc. Although we both had warmer clothes, we didn't put them on, figuring "we'd be gone soon". It was perhaps 25F and somewhat breezy at the summit.
After eating some snacks, we got really cold and decided to hurry out.
In the hurry, somehow, I managed to drop my sunglasses -- into my backpack -- without realizing, so I fished around in the deep powder snow for a while looking for them.
The two backpackers were super nice and helped me in my search (thanks, whoever you are!) but I eventually found them inside my pack.
But minutes had passed.
At this point, partner and I were really cold - hands numb, it was after 3pm (sunset at 5pm ish) and we started racing back. I realized my partner wasn't holding her ski poles since her hands were frozen. I was concerned about her risk of falling vs. frostbite. Stop her and warm up? Or continue We decided to just keep moving, since usually you warm up, right?
The snow had changed quite a bit (a frozen layer) and our downward trek was slower than we thought.
Good news: We were prepared and had GPS tracking (Delorme InReach SE), headlamps, we brought out at dusk. We had warmer clothes but just never put them on.
We made it to the ranger station a little after sunset, and at that point were warmed up and felt safe (aside from the black ice!)
* Super thanks to those two snow hikers who helped me look for my missing sunglasses (which were in my pocket).
* Appreciation for how it can all go wrong. We had perfect weather, perfect information (GPS, Weather, nav data, etc.) and yet we got ourselves into a mildly hypothermic state and made some questionable decisions.
* Moral: when stopping or summiting, first put on all your warm clothes now. Worst case: you can decide later that you are too hot. More likely: you get cold and make stupid decisions that cost you more time than had you put on the warm clothes.