Heating effects in polypyrrole-coated polyethyleneterephthalate (PET)-Lycr(R) fabrics were studied. Chemical synthesis was employed to coat the PET fabrics by polypyrrole using ferric chloride as oxidant and antraquinone-2-sulfonic acid (AQSA) and naphthalene sulfonic acid (NSA) as dopants. The coated fabrics exhibited reasonable electrical stability, possessed high electrical conductivity, and were effective in heat generation. Surface resistance of polypyrrole-coated fabrics ranged from approximately 150 to 500 Omega/square. Different connections between conductive fabrics and the power source were examined. When subjected to a constant voltage of 24 V, the current transmitted through the fabric decreased about 10% in 72 h. An increase in resistance of conductive fabrics subjected to constant voltage was observed. (C) 2005 Wiley Periodicals, Inc.