Two "seriously ill-equipped" paragliders who had to be airlifted to safety after becoming stuck high on a mountain near Crianlarich in Stirling.
The men attempted to climb the 1,174m (3,852ft) Ben More, but became stuck on icy ground above the snowline.
One of the three managed to make it back to the road, but the other two had to be rescued by RAF helicopter.
Police said none of the men had ice axes or crampons and were dressed in jeans, trainers and light jackets.
The group set out from Ben More Farm on Saturday with the intention of paragliding from high on the northern slopes of the Munro.
After reaching the snowline, but finding that conditions were not suitable for paragliding, they attempted to go higher but became stuck at about 970m (3,182ft) in "treacherous" conditions, police said.
One of the party was able to slide off the ice field, but the other two were unable to move on the "precarious" steep slope without ice axes or crampons and dialled 999 as darkness approached.
The leader of Killin Mountain Rescue Team, Billy Stitt, said all three were given "counselling" on the mistakes they had made after the rescue.
He said: "People have just got to be aware of the conditions and go equipped for them.
"It was pretty ridiculous what they were wearing. It was a lovely day on Saturday, but it does not take an expert to look at the hill and see what was there."
Central Scotland Police said it had been a "memorable" 25th birthday for one of the men and that all three were "relieved" to be rescued unharmed.
A police spokesman added: "Please please can people, no matter what your chosen sport or enjoyment is, be prepared for the conditions when venturing into the high ground and wilds of Scotland.
"Do not go beyond your limitations or what you are equipped for. Ben More is a serious mountain and people have sadly lost their lives there before."