Last week was really cold & snowny in KC, my garage was about 35 F & my pressures were all about 32 psi. I decided to pump the tires up to 36 psi .... cause I was going to work an evening shift & there was a chance it was going to be about -10 F when I got off work. When I took the compressor off the last tire....the little core valve stuck "in".....try as I might I couldn't get it to pop back out.....till I sprayed WD-40 in there.....