hot all the time!

I thought I was hot before I had this baby, but for the last couple of
months it is all I can do to keep from sweating up a storm. Is this a
normal part of postnatal hormones or what? I am breastfeeding my 4.5
month old, he feeds every 1-3 hours. I find I can walk around outside
with only a t-shirt when everyone else is in coats and scarves. Wierd!
Has anyone else had this experience? When did it even out for you?

Alicia