The 75-pound loggerhead sea turtle was discovered by volunteers from the Massachusetts Audubon Sanctuary at Wellfleet Bay and was taken to the New England Aquarium in Boston for a slow but steady warmup.
The aquarium said Herb's body temperature was in the 40s when he was found on the beach in Truro on Dec. 3. Veterinarians and rescue biologists slowly warmed him about five degrees each day, and his body temperature is now in the low 70's.
Herb, who was also suffering from an eye infection, is not the only sea turtle rescued from Cape Cod in a state of hypothermia this season, but the loggerhead turtle does have one distinction.
"This particularly guy, Herb, is the biggest of the season," said Tony LaCasse, a spokesman for the New England Aquarium.
He said the aquarium staff hopes Herb will be well enough to be released back into the sea in late spring or summer. He said up to 90 percent of the stranded turtles taken to the aquarium survive, and up to 98 percent of those are eventually released.
LaCasse said Herb's plight wasn't unusual. About 10 to 20 percent of the sea turtles washed ashore on Cape Cod beaches in the fall die because of the cold. But partly because of an early cold snap in November, for about a weeklong period the mortality rate was 60 percent, LaCasse said.
So far this year, a total of 62 stranded sea turtles have been taken to the aquarium.
Herb is likely between 4 and 7 years old. As an adult, he will weigh 200 to 250 pounds.