A temperature measuring device is provided which measures the total temperature T1 of an airflow based on the measured temperature T of the airflow flowing over the surface of an approximately blade-shaped casing arranged within the airflow flowing into an engine of the aircraft. The shape of the casing is set such that lumps of ice and snow, which may form on a surface of the casing and which may thereafter detach from the casing and strike the engine, detach at a stage of growth at which they do not cause damage to the engine.