There was no wind. The air was thick with "choking smoke" and a funnel web spider scuttled across his path on the fire trail.

"It was just very eerie," Moir said. "It is so dry out in Bilpin and I grew up in the region.

"There's a lot of grass out there which is really dangerous. Once things take hold they tend to exponentially get worse."

Moir spent Sunday night with firefighters battling to outwit the fires raging across NSW.

The temperature dropped to about 13 degrees overnight but it was still uncomfortably hot near the flames.

"You can imagine how uncomfortable it is if you have to run on a 45-degree day," he said.

Moir said the strike teams lighting the fires were organised with military-like precision.

"There's a real art to it, being able to read the ground ahead of you."

It was "hungry, thirsty work", he said, but the sense of camaraderie among the strike teams was palpable.

"There's plenty of jokes. You've got to keep your spirits up."

Read the latest update here and see the latest photos from the State Mine fire near Lithgow.