Effective first aid and the fast response of emergency services may have saved the life of an Auckland construction worker.

The worker suffered a significant wound in an accident at a Herne Bay building site yesterday morning.

It's understood to have involved a concrete-cutting grinder.

He was treated on-site and transported to Auckland Hospital by St John.

A doctor from the Auckland Westpac Rescue Helicopter Trust treated him in the ambulance.

The man is now a stable condition, and the trust have cold blood available.