Through ethnographic accounts, the method of heat treatment of silica materials to improve the flaking qualities is shown to have been known almost worldwide. Some Mesolithic and Neolithic flint artifacts from southern Sweden were examined in order to determine if they too were heat treated. From several methods proving or indicating thermal alteration of flint, analysis using scanning electron microscopy was chosen. Two samples were taken from each artifact, one being examined unaltered, the other being heat treated. No two samples from the same artifact had the same kind of surface appearance. Thus these analyses prove that the artifacts examined had not been heat treated. -- AATA