Mr Stead and his other companion, Magnus Flock, reached Mr Blair and contacted emergency services by cellphone.
As they waited for the Youthtown Trust rescue helicopter to arrive from Taupo, they smoothed out the snow to make sure Mr Blair was lying flat, moved him onto a mat they had in a backpack, wrapped him in more clothing and made a wall of snow around him to keep the wind off him.
The rescue helicopter dropped four members of the Turoa ski patrol team at the scene, and Mr Blair was moved on to a stretcher.
The group carried him about 50m to a ridgeline, where he was loaded on to the hovering helicopter.
Mr Blair was admitted to Rotorua Hospital with multiple injuries, including a broken left leg.
Yesterday, he was recovering in the orthopaedic ward after surgery on his leg.
Helicopter pilot Hendry de Waal said Mr Blair had lain on the mountain for about 90 minutes so also had hypothermia.
The hour-long rescue was difficult in winds blowing up to 45km/h, Mr de Waal said.
Mr Blair and his companions had travelled from Auckland on Friday night with other members of the New Zealand Alpine Club to spend the weekend on Mt Ruapehu.
His parents, Barton and Bernice Blair, received a call at their Pakuranga home about 9pm on Saturday to say their son had been injured in an accident.
Last night they said they still didn't know the details of how he fell.
Barton Blair travelled to Rotorua Hospital yesterday morning to be at his son's bedside.
Mr Stead said all three in the group had had a couple of seasons of experience on Mt Ruapehu, and what had happened was a freak accident.
* A climber survived a 300m fall in the Mt Somers-Stavely area, southwest of Christchurch, yesterday afternoon.
He contacted emergency services about 1.10pm, although communication was difficult because of his location.
The Westpac rescue helicopter, with St John paramedics on board, picked him up after a police search and rescue mission and he was flown to Christchurch hospital with moderate injuries.