He does not eat or drink anything cooler than 85 degrees, which is the same temperature at which the rooms in his house are set. Two electric heaters run continuously in his bedroom. For David Guessford, 38, of Hagerstown, Md., a breath of cold air could be lethal.

Since December Guessford has suffered from cold agglutinin hemolytic anemia, a temporary but potentially deadly blood disease, which in his case followed a bout with pneumonia. It is a rare disorder in which antibodies produced by white blood cells would destroy his red blood cells if he were not kept constantly warm.

"This could run for two months, four at the longest," was the prognosis of Dr. William R. Bell, a hematologist at the Johns Hopkins Hospital. But Guessford objected to being confined to a hospital room, so Bell called the National Aeronautics and Space Administration in Houston, which put him in touch with the company that manufactures space suits for NASA. The company lent Guessford a $650 airtight thermoplastic outfit used as protective gear for NASA's ground crews. As a goodwill gesture, a Virginia company contributed air compressors to inflate the suit, and a Hagerstown company donated three portable oxygen tanks so Guessford could be mobile. Thus equipped, he was able to journey home on Jan. 15 (in a heated van) and return last month to Johns Hopkins for a checkup. There Dr. Bell gave Guessford the good news: His red blood cell count was 43 percent. (It had been as critically low as 14; normal for males is 40 to 50.) Said Bell: "He should be out in a month."

That was heartening indeed for Guessford, who lost an eye in a 1967 car accident and had a kidney transplant in 1976. He credits the Bible and his wife, Michele, for helping him in his latest ordeal. "I don't expect my life to be all roses, but I do hope it improves," says Guessford. Meanwhile he's planning a trip this summer to South Carolina's Myrtle Beach. "I'm a warm weather person," he says.