Inspector Krissy Raine was called to a stricken sheep in Yarm, Cleveland, North Yorkshire on Sunday, March 18.
It is thought the sheep may have been worried by a dog and had fallen into a nearby river. The local fire and rescue service were able to pull the sheep from the river before inspector Raine could attend.
She then stayed with the sheep until a vet was able to arrive.
Inspector Raine said: “The weather was absolutely horrific, it was sub zero temperatures. It was a Sunday so the local vets were all very busy and I was being told it would be a few hours before anyone could get to me
“I got a silver blanket out of the van and wrapped the sheep up in it, I myself was head to toe covered in mud.
“I used to be a vet nurse before I worked at the RSPCA so I knew what to do to help him.
“He was hypothermic, his eyes were rolling back in his head and he was in and out of consciousness. I used towels to try to get as much water from the fleece as possible.”
Eventually, with the help of a vet, Inspector Raine was able to carry the sheep to her van and then onto the vet surgery. She then used a heat lamp to gradually bring the sheep's body temperature back up. The sheep was then able to make a full recovery and was able to be returned to the farm he belonged to.
Inspector Raine added: “This just goes to reiterate that dogs should always be kept on leads as we think this sheep may have been spooked. Especially as it’s lambing season now, we need dog walkers to be as considerate as possible when out in the countryside.”
To help the RSPCA continue to rescue, rehome and rehabilitate animals, visit www.rspca.org.uk/give.