In the winter of 2001-2002, we were concerned one cold night that the pet corn snake “Cornpuff” of my daughter's half-brother (he is not my stepson, the mother of my daughter wants it perfectly clear) had frozen to death. She had her head pushed up against the wire mesh covering the top of her cage, but she wasn't moving. The mother of my daughter and I thought she had somehow gotten stuck there and died. Her eyes were open but weren't moving. We know not to tap on a snake's cage under normal circumstances, but the mother of my daughter ended up banging on the cage trying to elicit a response from the stiff snake, with no response.
I gently took the wire off the top of Cornpuff's cage and touched her. She didn't respond and her skin didn't feel the way it normally did. I tried to push her down. There was no feeling of resistance from her, but she seemed frozen in place. Her eyes never moved. I told my daughter's half-brother the snake was probably dead and we would take care of her in the morning. I still was hopeful though, so I turned the thermostat up in the hallway to heat the place up a bit. In the morning we found her in her usual place underneath her little hidey house. She got a mouse and fresh water that day.
Note: this picture was not taken that night, but shows her in a similar pose.