Through the falling snow, the Tibetans had walked and climbed for three weeks, covering 600 miles of icy and mountainous terrain in their desperate bid for freedom.
By the time they reached Nepal, the freezing conditions had claimed the lives of five of their number; a 16-year-old monk and four children aged 11 and 12, whose bodies were left as they fell.
Claire McNaughton and her boyfriend Stuart Findlay, who were on trekking holiday, had just stopped for a cup of tea at the top of the 19,000ft- high Nangpa-la-a pass when one of the Tibetans, a young Bhuddist nun, sat down beside them. As she took off her shoes and socks, they stared in shock at her frostbite.
Ms McNaughton, 32, told The Independent yesterday: "We realised that if she didn't get medical help, she would have serious problems with gangrene."
Ignoring advice from other Western trekkers not to get involved, the Edinburgh couple resolved to help the nun and her companions.
"They had been walking for three weeks wearing little and they only had thin tennis shoes on their feet. They were on the point of death and I think they knew it," said Mr Findlay, 36.
"They were still walking but most of them were hobbling and their only possessions were the clothes they were standing in. We decided that we had to help two of the ones who were suffering the most."
One 11-year-old Tibetan girl was suffering from exhaustion and Mr Findlay took her in his arms, while Ms McNaughton and four hired porters helped the nun as they walked for nine hours - climbing a total of 3,000ft in the process - to a hospital established by the mountaineer Sir Edmund Hillary at Khunde, near Namche Bazaar, 90 miles north east of Kathmandu.
They then contacted representatives of the United Nations High Commissioner for Refugees, who arranged for a rescue party with horses to help the other Tibetans.
Mr Findlay said: "We trekked after them and found them in a terrible state. Many of them were close to death and we had to get them out of there as soon as possible."
The Nepalese police provided the horses to carry the Tibetans to a refugee camp and later flew them to Kathmandu where they were treated for frostbite and exhaustion.
One 22-year-old man had to have both his legs amputated below the knee.
The 21 refugees had been on the run from Tibet - a country whose plight was recently brought into sharp focus by the film Seven Years in Tibet, starring Brad Pitt.
The dreadful weather conditions make this the most popular time of the year for Tibetan refugees to make the crossing as they rightly believe that border patrols are at a minimum.
Ms McNaughton said that some of the children were being sent to Nepal to join schools run by the exiled Tibetan government in India because they are so opposed to schools in Tibet, which are controlled by the Chinese. Many of the adults were hoping to join monasteries or nunneries in India.
The Scots couple had spent two months trekking in Nepal, when in December a snowstorm hit the Himalayan region near Mount Everest. Within 36 hours, more than 3ft of snow had fallen, leaving many mountain-side villages isolated.
Ms McNaughton, who runs a small garden nursery in Edinburgh, and Mr Findlay, who is currently unemployed, returned to Scotland two weeks ago.
Ms McNaughton said they hoped to return to the Himalayas to see how the Tibetans were recovering.
"My lasting memory is a mixture of the shock of seeing how badly injured they were and of being able to help another human being even though you were unable to speak to them. There was a bond between us," she said. "We have also had first-hand experience of the tragedy that is Tibet and that has opened our eyes."Reuse content