This pumpkin has been filled with thermite. Thermite is a mixture of iron oxide and aluminum powder that you light with a strip of magnesium. Thermite burns at 3,000 degrees celsius. That is some freakin hot stuff. That's OK because Dale the guy who sent in the pictures is obviously a bad dude. In fact, in a knife fight between Dale and all of the other 2004 contest winners I would say that Dale could beat them all.
Be sure to check out what the pumpkin looked light after the thermite experiment. Dale says that pumpkins make great thermite containers because they are made up mostly of water.