An integrated perfusion apparatus or device for use in e.g. extracorporeal membrane oxygenation, cardiopulmonary bypass, or isolated organ or limb perfusion, comprises a blood pump for circulating blood through the device; a blood oxygenator for oxygenating blood, and at least one heat control unit capable of controlling and/or regulating blood temperature within the device, wherein the at least one heat control unit comprises at least one solid state heating and/or cooling source, such as at least one Peltier device. The invention also relates to a method of performing perfusion on a patient, limb or organ, comprising using the perfusion device.