A man was taken to hospital with burns to his hands and face after a chip pan blaze.
Firefighters said the man, aged in his 20s, attempted to extinguish the flames with water, which caused an explosion.
Crews were alerted to the incident on Morland Road, Gleadless Valley, at 8.20pm on Thursday.
Firefighters are using the incident as a reminder of the dangers of putting water on burning oil.
A Fire Service spokesman said: “Pouring water onto hot oil makes the water expand rapidly, displacing the oil, causing a spectacular, but lethal, explosion.
“Please don’t use chip pans and never leave hot oil unattended.
“If a fire does start, don’t attempt to tackle it yourself - get out, stay out and call 999.”