The blaze broke out at around 3pm on Saturday (August 3) on Cheviot Drive in Scawthorpe, Doncaster, after the man poured petrol onto a garden brazier.
The fire quickly spread to a shed.
Although the fire was out when a fire engine from Adwick fire station arrived on the scene, the man suffered burns to his hands and face, but declined medical treatment.
A spokesperson for the fire service warned people never to pour petrol onto a fire.