Yep, to an extent it’s something to be anticipated. Less body heat, partly due to less food undergoing digestion at any given time, alongside gradually declining insulation as fat reserves shrink.
I too used to be the guy who would in snowy weather drink his morning coffee by the open window dressed in just PJs and just dread the summer – boy has that reversed. Life is full of these humbling little ironies – formerly I couldn’t stand those who would never fail to immediately vocalize their subjective and perpetually swinging discomfort, of feeling hot to cold and hot again all within minutes; now I get where they’re coming from (but do my best to keep my mouth shut nonetheless, equipping cars with blankets if need be!).