Three firemen and an ambulance crew member sent to rescue hikers ended up being stranded themselves, as dense fog descended on a Sai Kung hill.
The rescuers and the four hikers were able to walk out yesterday morning, after spending the night in the rugged Sai Kung East Country Park.
The poor visibility and darkness foiled efforts by a Government Flying Service helicopter to pick them up on Tuesday evening.
The four hikers, all men, set out on a trek in the country park on Tuesday. As they reached Mai Fan Teng - a ridge above Tung Wan on Big Wave Bay - one of them developed leg cramps and could not continue. They called police at about 4.30pm, using a mobile phone.
The three firemen and an ambulance crew member were airlifted in around 5.30pm to conduct a search. About two hours later, the rescuers found the hikers and attended to the man with leg cramps.
But fog, then darkness, cut visibility and prevented a helicopter from picking up the group, said Senior Station Officer Tse Lap-yip of the Fire Services Department. Since one hiker could not walk down the hill, the rescuers decided to spend the night with them.
'At the time of the incident, it was very foggy and windy, and the visibility was [down to] three metres,' he said. 'The path is very steep and rough. It was dangerous to carry an injured hiker and lead the other three to walk down the hill in the dark.'
The eight men had to share biscuits, candies and water during their ordeal, but they were safe and they kept contact with the fire station overnight, Mr Tse said.
In the morning they walked to the shore and were picked up by a Marine Police launch. The 42-year-old hiker who had cramps was treated at Tseung Kwan O Hospital and discharged.