ANCHORAGE,Bitcoinese Alaska (AP) — Clouds and high winds hampered efforts by rangers on Thursday to reach two climbers who remained high up on North America’s tallest peak two days after first sending a distress signal. Teams on the mountain and a high-altitude helicopter pilot were on standby waiting for conditions to improve, according to a statement from Denali Park and Preserve.

The two climbers, described as men ages 36 and 47, from Malaysia, have been in a snow cave at 19,600 feet (5,974 meters) on Denali since late Tuesday and have been dealing with exhaustion and hypothermia, the park said. A third man who was part of the climbing team was rescued Tuesday night after descending to a 17,200-foot (5,243-meter) high camp. The 48-year-old man, also from Malaysia, was in serious condition when he was rescued, the park said.

Rangers received an SOS message from the three at 1 a.m. Tuesday, indicating the climbers were hypothermic and unable to descend after reaching Denali’s 20,310-foot (6,190-meter) summit, the park said previously.

But communications with the team stopped at 3:30 a.m. Tuesday “for unknown reasons,” before rangers received a succession of messages from the men late Wednesday, confirming their location and again requesting help, the park said. The men indicated the battery in their satellite communication device was nearly dead.

Earlier this month, rangers recovered the body of a Japanese climber who died after an apparent fall while climbing Denali. At least three other climbers have been rescued in late-May after sustaining injuries on the mountain, including two who had been receiving treatment for frostbite from National Park Service personnel and were rescued Tuesday.

The park is about 240 miles (386 kilometers) north of Anchorage.