SHOW LOW, Ariz. - Two U.S. teenagers were rescued after spending two cold hours hanging onto a dead tree after ice on a lake began to crack, authorities said Thursday.

The Arizona teens were taken to a hospital for treatment of mild hypothermia after being rescued Wednesday, Show Low Fire District Capt. Brent Mix said.

"Their hands and feet got pretty cold," Mix said. "It was dark by the time we got them to shore."

The boys were rescued after a firefighter crawled across the lake with a rope that was used to pull a boat carrying two other firefighters.

The teens got in the boat, and it was pulled to shore, Mix said.

It can be particularly dangerous to try to walk on ice on Arizona lakes because temperatures usually don't get cold enough for the ice to freeze solid, said Kirk Webb, a spokesman for the Lakeside Fire District.

"Every once in a while we have kids trying to see how far out they can go," Mix said. "That was pretty foolish."

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