Although not a replacement to a traditional fire extinguisher, a fire blanket can be a very useful adjunct to one. Fire blankets work by smothering the fire. They work very well on small fires, and they are particulariy useful in two common circumstances: Small pan grease/oil fire- here, you needn't ruin the food and make a big mess by spraying chemicals over everything on the stove top. When a person's clothing has caught on fire- again, here the chemicals could cause extra problems if they get into the eyes or mouth.