Make them drop and roll
You must try to persuade the person on fire to lie on the ground then roll. This can put out the fire as a result of preventing it from catching oxygen from the air.
Roll them in a smothering item
According to a Quora thread, a person who is on fire should be rolled in a smothering item if possible. This can help extinguish the fire.
Don’t use a wet bandage
According to a firefighter, if the person has more than 10% body burns then using a wet bandage to protect them might cause hypothermia.
Use a fire blanket
If you have a fire blanket, roll it around the person. This can help extinguish the fire.
Use a heavy, tightly-woven fabric
If you don’t have a fire blanket, use a heavy, tightly-woven fabric. Avoid open weave fabrics or or any synthetic materials that are not specifically fire rated.
Don’t cover people up immediately
Don’t cover people up immediately after the fire is put out because this can trap the heat from brunt skin or clothes.
Use water to cool the burnt areas
You can use water to cool the burnt areas of the person’s body.
Make them jump in water
If there is any water surface near by, such as a pool, jumping in it would stop the fire. This must happen immediately after the person catches fire.
Running makes it worse
When a person who is on fire runs, the flames get fanned and so they grow. (See Why Are Fire Trucks Red?)
Do not use synthetic materials
Synthetic materials can easily catch fire and make the matter worse. When you cover a person with something, make sure it can’t catch fire easily. Avoid using fabrics made of rubber or nylon.
Do not pull their clothes
Pulling away clothes might take off parts of the molten skin. Avoid pulling away clothes.
Do not let the person drink
Smoke inhalation makes the throat swell. Do not give the person anything to drink.
Keep them warm
When the skin burns, the body might lose the ability to control its temperature. Keep the person’s body warm until help arrives. (See What Is the Color of Fire?)
How to put out someone on fire?
What to do if someone catches on fire? What are the best ways to put out a fire on a person?