Man remains calm despite being on fire

A man with his clothing ablaze has surprised onlookers by calmly walking down the street without uttering a word.

The man was filmed by a concerned witness on an unknown street in New York City with his pants, T-shirt and jacket consumed by flames.

The onlooker approached the man and asked if he needed any assistance, but he did not respond and started walking back in the other direction – leaving a path of glowing embers in his wake.

"This guy is on fire. What the heck," the man said in the 30-second video.

"Hey are you okay? Are you good?" he asked as the man peeled off his black jacket.

The footage was uploaded to NYCFireWire's Twitter account on Monday but no details have been revealed about who filmed the incident or what happened once the camera stopped rolling.

Social media users questioned why no one put the fire out, while others suggested he may have been "high on something not to feel that".