A car driving through thick smoke to escape a bushfire in Bilpin, NSW, has hit a man trying to combat the blaze.

Video of the aftermath shows a firefighter limping over to his crew mates before collapsing to the ground in pain.

Two others help pick up the injured firie and help him into the firetruck, struggling to get him inside the vehicle.

Firefighter a second after being hit by a car in thick smoke as fire roared through eastern Bilpin (Nick Moir)

Video of the aftermath shows a firefighter limping over to his crew mates before collapsing to the ground in pain (Nick Moir)

He was rushed to hospital with a suspected leg fracture.

The incident prompted a reminder from Fire and Rescue NSW.

"If you are on the road, please be reminded that the speed limit is 40 km/h around emergency vehicles," they tweeted.

Bilpin is one of the worst hit regions in NSW, with major fires causing mass evacuations.