Ambulance Victoria has confirmed a patient in his 50s was taken by road ambulance to Ballarat Base Hospital in a critical condition.

UPDATE 2.25pm:

Plans to winch out a hiker who has collapsed in difficult terrain at Mt Buninyong have been hampered by high winds.

The SES said Ballarat volunteers with a mill (one-wheel stretcher) have worked with police and paramedics to carry the man down a track to the Blackberry Lane area at the base of the mountain.

PREVIOUSLY:

A helicopter has been dispatched as emergency crews rush to save a man in his 50s who collapsed on the Goldfields Track near the summit of Mount Buninyong.

High angle rescue trucks have been called to assist Ambulance Victoria and SES volunteers with extracting the man from steep terrain up the mountain - the initial alert went out just after 11am Sunday, with additional reinforcements called in just before 12pm.

Ballarat SES volunteers are at the scene with a stretcher to carry the hiker out to a nearby clearing, where an air ambulance was due to arrive.

An Ambulance Victoria spokesperson said the man is in a serious condition - and any attempt to carry him on a stretcher to a waiting road ambulance would take about 40 minutes.

It was unclear if the man would be winched out.

The air ambulance arrived from Essendon airport within 25 minutes.

Wind conditions in Ballarat at the time of the helicopter's arrival were gusting to about 44km/h.

MORE TO COME

Have you tried The Courier's app? It can be downloaded here.