A man and five teenagers were rescued today after they were reported missing on Carrantuohill mountain in Co Kerry.
Kerry Mountain Rescue searched the area after the six people were reported missing at about 1am.
Brendan Coffey of the rescue service said the man was suffering from severe hypothermia and exhaustion. He was airlifted to hospital by the Shannon-based rescue helicopter.
The five teenagers were given food and drinks and were fine, Mr Coffey said.
He said the rescue team of 20 had originally searched an area known as the Devil's Ladder, an area on the descent from Ireland's highest mountain. They were later found on the other side of the mountain, however.
Some of the climbers were experienced and some were not, Mr Coffey said.
"[There were] five teenagers who seemed to know the area, but they had one gentleman with them who seemed to be inexperienced and he was suffering from hypothermia. He was exhausted by the time we got to him. We had to stretcher-lower him down some pretty difficult ground.
"He's just been airlifted to Tralee General Hospital."
Mr Coffey told RTE's Morning Ireland the teenagers would be "fine". "They were cold and wet but by the time we'd given them some warm drinks and food we got them moving again. They were okay."
The mountain rescuer urged climbers to prepare properly before undertaking any climb.
"I suppose the most important thing even in the summer time is to allow plenty of time. Go out early in the day. If you go out late in the evening, that's when the problems start really."