A Salt Lake man who survived two nights in the Uinta Mountains after becoming lost on a snowmobiling excursion died of severe hypothermia just hours after he was rescued Monday, a hospital official said.

LDS Hospital spokesman Tim Madden said the man's body temperature had dropped to 43 degrees after his ordeal. He was pronounced dead at 3:16 p.m.Madden said the man's name was being withheld pending notification of next of kin. Authorities have said the victim was a 31-year-old, believed to be from Salt Lake City.

The man was found about 10:40 a.m. Monday in steep, snowy terrain in the vicinity of Mirror Lake in the western Uintas, a Summit County sheriff's dispatcher said.

He was transported by sled to a lower elevation by three search and rescue members and then flown by helicopter to LDS Hospital.

Madden said doctors labored to raise the man's body temperature, putting him on a heart-lung bypass, but the effort failed. The body was to be turned over to the state medical examiner's office for an autopsy.

Crews from Summit and Uintah counties began looking for the man Saturday after he became separated from two companions. His abandoned snowmobile was found late Sunday, but the search was discontinued Sunday night due to bad weather.