All my life so far, I was told to cover my ears and keep the feet warm if it’s terribly cold weather. On this trek, for the purpose of getting accustomed to the higher altitudes, I learned otherwise about covering ears. Our trek leader insisted that we cover our head (with skull cap/ sun cap/ bandana) but keep the ears open, as that helps us in getting acclimatize. Nothing specific about feet (shoes/ just socks/ open sandals/ flip flops, all were accepted).
Also, no afternoon naps. We stopped around 3pm or so on Day 2 because terrain was tough that day; a mix of steep ascents, boulders, crossing a water stream of freezing temperature, etc. We were obviously tired and the idea of getting into the tent and lying down was simply irresistible. However, that was against the acclimatization. So, he kept us occupied with snacks, tea, card games and stuff but did not allow to doze off even for a minute.
I had a mild headache two days in a row because of altitude change. Trek leader said that’s perfectly normal and advised to walk it off, but I preferred a normal headache pill to be active and move around. A nap works fine for mild headache but as that was in the not-to-do list, I had to swallow some mild medication.