cold sweats at night?

For the past few months, I've had to go to bed with the window open (it's december in Minnesota). It's the only way my pillow doesn't feel like a hot coal. I quit drinking at night to see if this would help, but it's only getting worse. I can wake up two hours, four hours, whatever......cold, but my neck, bra straps, and my hair is drenched in sweat. I'm always cold when I get out of bed, but it doesn't matter how cold I am. I'm female, late twenties and not pregnant. But what is going on? It's only at night and as soon as I lay down or get ready for bed my body feels like a space heater.