Taupo's Greenlea Rescue Helicopter has been kept busy in the last 24-hours with numerous call outs including a search and rescue operation.

This morning the rescue helicopter was initially called to the upper reaches of the Tongariro river to a youth who had suffered a period of unconsciousness.

The 17-year-olds rafting party was located and he was airlifted to Taupo Hospital for observation.

At the same time requests were made by police in assisting with delivering some search teams onto Mount Pihanga as part of a search and rescue callout involving police and land-sar volunteers from Turangi.

The search involved a 22-year-old Australian living in Turangi who got lost yesterday while on a day hike to the summit of Pihanga. After reaching the top the weather closed in and he lost his way.

Starting his trek at midday, the man called police at 5pm after being unable to find his way out.

Search and rescue teams were out until midnight looking for the man before resuming this morning. He was found by searchers and the Greenlea rescue helicopter as they were being flown to the summit of Mt Pihanga.

The man was wet and cold and hypothermic after spending a cold night out on the south facing sloped in a strong wind.

He spent the night huddled in the sub alpine bush and had remained in the same place since calling police yesterday. His cellphone battery had gone flat following his second call to police around 8 last night.

He has since been discharged from hospital.

Senior Constable Barry Shepherd says the search teams did a sterling job in some pretty inclement weather conditions and it is good the young man was found when he was.

'If there is one message out of this whole event it is that people need to tell someone where they are going and when they are due back."

Having just returned from Taupo hospital the helicopter was immediately dispatched to Reporoa where a 62-year-old man suffered a serious medical event while working around home. He was flown to Rotorua hospital.