Three people were rescued from Snowdon after getting into trouble on the Pyg track.
One of the three, who were all medical students from London, was evacuated by stretcher with hypothermia before being taken to the Ysbyty Gwynedd in Bangor.
Twenty members of the Llanberis Mountain Rescue Team were involved in the operation, which took more than four hours. The three walkers raised the alarm from their position about 750m (2,460ft) up the 1,085m (3,560ft) peak. All three were suffering from cold in the poor conditions including high winds and heavy rain.
Although wearing waterproof jackets, the trio were not well equipped, according to rescuers. They are appealing for anyone venturing on to the mountains to take account of the weather and equip themselves appropriately.