I usually make my own fire hazards. It takes about 30 minutes.
All you need are cheap paints, cotton balls and adhesive spray paint and see through containers..
I went to the dollar and game store and bought cheap transparent containers.
Cheap yellow, orange and red paint..
You paint dabs.. dabs mind you.. of the 3 colours inside the containers. Make sure there is space to see through a bit of the black and white cotton balls and not totally painted over...
While the containers are drying over, spray paint the cotton balls black...
Spray adhesive glue within the container and, after you put the blackest cotton balls, spray paint the cotton balls again with the adhesive glue so they stick together and you have glue for the top of your most bottom layer.
Keep repeating this until you get 3 layers (or as many layers as you want), with less and less black cotton balls..
Third layer put on top and stuck with sprayed adhesive glue..
Lightly spray black.. and voila, you got fire hazards to place on your battlefield. You can place them on destroyed vehicles or terrain for instance..