US Patent 10117491 Hand held appliance

A hand held appliance, such as a hairdryer, includes at least one fluid inlet for admitting fluid into the appliance, at least one fluid outlet for emitting fluid from the appliance, at least one fluid flow path extending through the appliance, a heater, and a fluid chamber at least partially defined by an external wall of the appliance, the chamber being configured to provide a thermally insulating barrier between the heater and the external wall. The fluid flow path comprises two parallel sections.