Sounded like a lot of people got in over their heads this weekend.
I was cold on Mount Mansfield wandering around, but it’s only 4,000ft and I know I can get down rapidly on foot. MWN is 2,000 feet higher (10F usually). The tourists were still in autumn mode.
I always travel prepared this time of year with the basics of change of base layer if get sweaty on the way up, plus gloves and hat this time of year. It’s crazy how much those things matter. You could be in shorts even (not ideal or recommended), but if your upper body core is warm with layers, head is warm, and hands covered… those are the keys to both comfort and survival.