Abstract: The invention describes a bimetallic thermal switch comprising an electrically insulating carrier (2), a contact spring (4) made from a bimetallic material, which is carried by the electrically insulating carrier (2) and has two ends, one being fixed in position, and which is so formed, at least over a certain portion (4a), that it will abruptly change its curvature when its switching temperature is exceeded; two electric supply lines (8, 9) held on the insulating carrier (2) and leading to two contact pieces (6, 7) disposed separately one from the other and from the contact spring (4); and a contact bridge (5) mounted on the contact spring (4) opposite the two contact pieces (6, 7).