Some of the group were wearing t-shirts and shorts as temperatures hit -10 degrees Celsius.
President of the Swedish Mountain Rescuers National Organisation, Rickard Svedjesten, has revealed that six Irish people were rescued from Sweden's highest mountain, Kebnekaise.
Svedjesten said on Monday that rescues on the 2,103 metre peak, which is part of the Arctic circle, are common at this time of year due to misleading good weather during the day which turns cold and windy after dark.
He told RTÉ radio’s Today with Claire Byrne that some of the climbers aged in their 30s had been wearing t-shirts and shorts, saying that a lack of preparation, "bad equipment and bad clothing” was part of the issue.
Svedjesten said that the group had called to alert them at 9.30pm on Sunday night, however, due to cloudy conditions, the rescue was postponed to morning.
He said the group was able to find shelter in a hut on the mountain through the night before being airlifted via helicopter to the closest road this morning where they were then taken to hospital.
"It started last night at 9.30pm. The Mountain Rescue got an emergency call," he said.
"It was that there were three climbers lost on the biggest mountain in northern Sweden, Kebnekaise, but that information was wrong.
"They were not climbers. They had no equipment, and their clothing was very bad."
Svedjesten said that temperatures can begin to plummet well below zero in late August and September in the region.
"There is still snow at the top and there are even glaciers in that area," he said.
"Last night, the temperature was below zero. It was -10 degrees Celsius."
He added that not checking the weather was a common mistake made by groups before embarking on mountain climbs and recommended that people check the Irish Mountain Rescue service website before attempting any mountain walks or hikes.
Svedjesten added that "everyone is fine" following the incident.
