A man is fighting for his life after being crushed between two 2.5-tonne shipping containers at a workplace in Sydney's west.

Emergency services were called to the packing supply warehouse on Liberty Road in Huntingwood about 7.25am, and arrived to find the 65-year-old man was no longer trapped but had serious injuries, NSW Ambulance Inspector Andrew McAlpine said.

A man was crushed between two shipping containers on Wednesday morning. Credit:Google Maps

"[He] was released by co-workers, he was in a life-threatening, critical condition," said the inspector, who was at the scene.

Mr McAlpine said the first paramedics provided "life-saving interventions" straight away, before the man was taken to a medical team who had arrived by helicopter.