Chilli owner Gagan Kaur said her husband Virender Singh had gone to the carpark at the back of the restaurant with another person when they found a man lying on the ground who was on fire. They helped extinguish the fire and called emergency services.
"Him and his friend saw this guy was burning, so they just stopped. One of them just pulled the guy and stopped the fire and my husband called the police," she said.
She didn't believe the person had any links to the restaurant and did not know his current condition.
A second person was believed to have received treatment for burns to his hands.
No further information was available from emergency services last night.
Four fire investigators and 10 police cars were at the scene.