Scott Schultz, age 9, of Eugene, Ore., for his question:

HOW HOT MUST IT BE TO HAVE A FIRE?

Before you can have a fire, you must have a fuel or a substance that will burn. Then the fuel must be heated to its kindling temperature. Finally, there must be plenty of oxygen for the fire to make the fuel burn.

Different fuels produce fires with different temperatures. The ubstance must be heated to the kindling temperature, or kindling point, before it will burst into flame.

Paper has a kindling temperature of 450 degrees Fahrenheit while wood can range between 375 degrees and 510 degrees, depending on the hardness.

The lower the kindling temperature, the more easily a substance will catch fire.

Cotton has a kindling temperature of 511 degrees Fahrenheit. Wood alcohol must have a kindling temperature of 867 degrees, while natural gas must be between 900 and 1170 degrees.