You can but there are some exceptions and you need to be careful. A frying pan with a plastic or wooden handle should never be used over a live fire. The potential for melting or burning is very high around an open fire, much more so than on your stove top. If you've got a ceramic-coated frying pan or porcelain-enameled frying pan, they could suffer chipping or fracturing in the high heat of a fire.
Campfires can reach up to 1650 degrees Fahrenheit, while non-stick pans can give off dangerous fumes when they get over 1000 degrees Fahrenheit. When you're trying to make sure you don't undercook food, you don't want to also worry about your cookware giving you health problems.