Sort of - now that I live in Michigan, and re-acclimated to a northern climate, at 21 I have to sleep on top of blankets or I overheat (though, I will find that after a few hours, my body cools down while sleeping and I may pull a blanket overtop me). 18 + a normal duvet is perfection. Cool enough for blankets, but not so cold that I feel uncomfortable.
This is mostly a meditation on the fact that I used to be able to sleep in temperatures of 26-27 in Singapore. The human body (at least this one) can definitely acclimate to local environments given some time and exposure.
Of course - no acclimating whatsoever will help you if the wetbulb temperature gets up to 35. You are just dead unless you can find some active cooling at that point fairly quickly.