Double layer recast Nafion® membranes reinforced using a polyethyleneterephthalate (PET) support were developed for PEFCs application at Tcell > 110 °C, low humidification and pressure. The investigation of chemical–physical properties suggested a probable interaction between PET and Nafion matrices. Electrochemical tests in a 25 cm2 H2/air PEFC between 80 and 140°C were carried using a pure Nafion as a reference. A short time test supplied an average stable current density of about 400 mA cm−2 (0.5 V) for reinforced membrane against an unstable trend of reference. High current densities of 530 mA cm−2 and 330 mA cm−2 (0.6 V) were obtained for N-PET at unusual temperatures (130–140 °C).