Back in 2012-2014 I also dropped heavily, roughly 120kg down to 65kg, and I felt colder, with body temp falling by a degree or more, from 36.9 to a steady 35-and-a-bit or barely 36. The body was evidently resisting calorie burning. Oddly, this round (145 kg to 65 kg) my temperature barely changed. Cold bothers me more now, though overall its a plus, since heat is far easier to bear, and adding a jumper is easy. Sweating less is a pleasant bonus.