The past few weeks I have been waking up sweaty, with a damp shirt and sheets. It never gets above 70 in the house and I'm usually cold at night and am under a comforter but I don't wake up hot, just sweaty. It happens every night, for the past few weeks. Before this I had no problem with this. Nothing's really changed. I have nightmares but I had nightmares before all this too, its part of my PTSD. Anyone know what causes this, or if I should be concerned?