Abstract: An exhaust gas muffler for an engine, the exhaust gas muffler having a body, at least one inlet for the exhaust gas from the engine on the body, a baffled chamber in the body to receive exhaust gas from the at least one exhaust gas inlet, at least one exhaust gas outlet from the baffled chamber to vent the exhaust gas from the baffled chamber, at least one fresh-air inlet on the body, a heat exchange conduit extending into the baffled chamber between the fresh air inlet and the at least one exhaust gas outlet, the heat exchange conduit being sized and shaped to permit heat exchange between the fresh air and the exhaust gas in the baffled chamber, and a fresh air outlet on the heat exchange conduit, the fresh air outlet being sized, shaped and located relative to the exhaust gas outlet to permit the fresh air to mix with exhaust gases being vented from the baffled chamber to lower an exit temperature of the exhaust gases.