Five people were treated for frostbite and hypothermia after a 500-mile journey in below-zero weather on an unheated Greyhound bus, a hospital spokeswoman said.

"If it hadn't been for my blankets, I think we'd be in worse condition than we are now," said Dan Clark of Missoula, Mont., who said his daughter was treated for frostbite at St. Luke's Hospitals-MeritCare after they arrived here Friday on the bus from Billings, Mont.A total of five people from the bus were treated for cold-related maladies and later released, according to another supervisor, who declined to identify herself.

The Forum newspaper of Fargo quoted one passenger as saying he blacked out for a half-hour from hypothermia. He declined to identify himself, the newspaper reported Saturday.

A Greyhound spokesman in Fargo, said Saturday that the bus' alternator failed at Forsyth, Mont., about 100 miles east of Billings and 500 miles from Fargo. The malfunction left the bus essentially without heat, he said.