Three Kiwis were among a group of six evacuated from Mt Everest after falling ill.
The trio were part of a 30-strong group of fellow New Zealanders and Australians hiking to Everest Base Camp earlier this month.
The group's Kiwi tour guide told the Herald they've been battling "extreme cold" with temperatures around -30C each day.
They were en route to base camp when, on January 4, six trampers - three Kiwis and an Australian - fell ill.
He said his group, which ranged in age from 20s through to 40s, was well prepared but were quickly struck with altitude sickness, an illness which almost strikes at random and could be serious if the affected person did not descend quickly enough.
Those affected had suffered symptoms including nausea, fatigue, high heart rate, shivering, low blood oxygen, diarrhoea and dehydration.
The guide, with help from his Nepal guide, managed to organise a helicopter to evacuate the affected guests off the mountain, from about 5000m altitude, to recover in Kathmandu.
He said there they received treatment including IV drips and antibiotics.
Despite some of the group falling ill, the remaining 25 continued on and made it to base camp.
Those who were ill were also now out of hospital and had recovered well, he said.
