A combination fluid path and mount for a heat exchanger of the type used to cool or heat blood or solution for cardioplegia by transferring heat between the blood or solution and a heat-exchanging fluid. The heat exchanger has an inner surface defining a passageway in which heat-exchanging fluid circulates. The combination comprises a body of generally flexible-resilient material having a periphery adapted to be received in the passageway of the heat exchanger. A bracket is provided for mounting the body on a support. The body has heat-exchanging fluid inlet and outlet passageways, each opening through the periphery for circulating the heat-exchanging fluid to the passageway of the heat exchanger. A fixing-sealing mechanism is provided for removably fixing the heat exchanger to the body and sealing between the body and the inner surface of the heat exchanger. The fixing-sealing mechanism expands a portion of the periphery of the body against the inner surface of the heat exchanger to form a seal therebetween and to hold the heat exchanger on the body. Heat exchangers specifically designed for use with the combination are also disclosed.