An exhaust path and a heated portion such as an air duct of an internal combustion engine are connected to each other by a heat pipe. A heat pipe working fluid (water) vaporized by the heat of the exhaust gas in a heat receiving portion of the heat pipe is condensed in a heat discharging portion of the heat pipe and heated in the heated portion by the heat of the exhaust gas. An outer cylinder is formed around the casing of the heat pipe, and the exhaust path and the heated portion are connected to each other through heat insulating members, while at the same time supporting the heat pipe body through heat insulating members.