It is a known fact that hyperthermia is a potent sensitizer to radiation as well as to many chemotherapies. However barely known yet is the interesting potential of hyperthermia to increase efficacy to the newly arisen immune therapies. This article briefly summarizes the mechanism of action in the therapy concept of checkpoint inhibitors and then explains the rational why hyperthermia facilitates and enhances these mechanisms. As conclusion the idea emerges to apply hyperthermia for an additional benefit to immune therapies. Especially attractive appears the fact that in the advisable temperature range no toxic adverse side effects are to be expected.