It was snowy and below freezing when Fluffy was discovered frozen.
The owners of Fluffy, who live in Kalispell, Montana, in the far northwest of the state, found her in a snow bank on January 31 - unresponsive, with her fur matted with ice.
Cats' temperatures are normally around 101 degrees, said the veterinarian.
"I've never seen this".
"Her temperature was very low but after many hours she recovered and is now completely normal", the clinic wrote on Facebook.
Dr. Jevon Clark of the Animal Clinic of Kalispell said Thursday (Friday NZ time) that Fluffy was unresponsive and her body temperature didn't register on the clinic's thermometers when her owners brought her in a week earlier.
Dr Clark said Fluffy was three years old and had always lived outdoors.More news: India crash to worst ever T20 defeat
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Clark told KTMF he and his associate, Dr.
So low the staff couldn't even measure it on their thermometer.
They rushed her to a nearby animal clinic to get her examined. "Fluffy is incredible!" the clinic said.
Facebook commenters sent their well wishes to the kitty and their congratulations to the clinic.
"These crabby cats are survivors", Clark said. They scooped her up and immediately drove her to the vet, which is probably what saved her life.
The cat was discharged to its owners the same night and when Dr Clark checked in a few days later, Fluffy appeared to be back to normal. They then used specialized heating pads and heated cages, which helped her to regain consciousness.