Non-stick pans are another story. When heated to temperatures of 360 degrees Celsius, (685.4 Fahrenheit for us folks in the United States ) Teflon-coated pans will release perfluorooctanoic acid, a likely carcinogen. Not that people often cook at temperatures that high, but now you definitely shouldn't. Chemicals released by non-stick pans can cause the death of pet birds. It can also cause flu-like symptoms in humans. Teflon-pan makers have made a deal with the EPA to remove the poisonous chemicals from non-stick pans by 2010. Consumer Reports claims that the pans aren't that dangerous, because of the extreme temperatures needed to release the chemicals. You're more likely to start a fire than anything.
Note: Remember, if the Teflon coating in your pans is all scratched up, don't use them.
Although non-stick and aluminum get bad raps, they seem to be only mildly dangerous in certain circumstances. In my personal opinion, I'd rather use other types of materials to cook my food. Why take a risk? But I wouldn't turn down food cooked in non-stick or Aluminum cookware or any food, really.