High temperature switch apparatus are disclosed. An example apparatus includes a first plunger housing having a first cavity and a second plunger housing having a second cavity. The first plunger housing and the second plunger housing to couple to enclose a plunger assembly of a proximity switch. A first contact housing defines a third cavity and a second contact housing defines a fourth cavity. At least a portion of the third cavity and at least a portion of the fourth cavity are complementary to a shape of an outer surface of the first plunger housing and the second plunger housing.