People are climbing Snowdon in jeans, fleece and trainers, rescuers said
A mountain rescue team who have had to rescue 17 people from Snowdon since Christmas Day are urging people not to walk unless they are properly equipped.
The latest emergency came after two men were left stranded 2,500ft (760m) up the mountain in the dark after their friends went off with their torch.
Around 20 members of Llanberis Mountain Rescue team were called out at 1800 GMT on Monday to help the pair.
The team's secretary said many people climbed the mountain in just trainers.
"It's fabulous weather here at the moment, the sun's shining and the mountains look beautiful," said Ian Henderson.
"But once you get out of the sun, it can be -10C with the wind chill and there is snow.
"If people are well equipped and experienced, it is fine to go up Snowdon, but we've had to rescue people from high up who are wearing just trainers, jeans and fleeces."
He said the team were called after two men were abandoned by their friends - another two men - at Y Lliwedd, a ridge high up the mountain.
The two men had felt unable to carry on as it was dark and the other men - believed to be in their 30s - went on without them, taking the torch and equipment.
The mountain rescue team were called at 1800 GMT and spent four hours taking the stranded pair to safety.
They then found the other two men, who said they had gone to find help.
"All the rescues we have had to make could have been avoided with better planning and better equipment," said Mr Henderson.
"People are putting themselves in danger."