Rethinking the Registry

So, one of the lovely gifts that we registered for was a down comforter, but knowing that we wouldn't actually be sleeping in a frozen tundra, we picked the lightest, or the 365-day, year-round duvet. We both like sleeping with a blanket, but I am seriously rethinking this duvet - it might have to be put in the closet until cooler temperatures prevail.
We've tried turning the thermostat down a few degrees, but it still gets ridiculously hot. I think that down is just too much of an insulator, especially for me, a person that sleeps next to a furnace. I really don't know how he does it, but my husband manages to exude heat, but once he gets out of bed, where he was laying is the coolest section of the mattress.