A heat exchanger has a multi-lumen tubing having one end connected to a supply fitting and another end connected to a return fitting. The tubing has a central lumen, a middle lumen that surrounds the central lumen and an outer lumen that surrounds the middle lumen. The supply fitting has an inlet, an outlet and a proximal port wherethrough an infusate is input to the heat exchanger. The supply fitting is configured such that its inlet is connected to the central lumen, its outlet connected to the outer lumen, and its proximal port connected to the middle lumen of the tubing. The return fitting is configured to establish a through passage between the central lumen and the outer lumen of the tubing so that a heating fluid fed through the supply fitting to the central lumen is returned to the supply fitting by way of the outer lumen. The return fitting further has a distal port configured to connect to the central lumen of the tubing, so that the infusate fed to the proximal port of the supply fitting may be output from the distal port of the return fitting, after passing through the central lumen of the tubing. As the infusate traverses along the heat exchanger, it is heated by the heating fluid that flows along the central lumen, and also by the rerouted heating fluid that flows along the outer lumen of the tubing. The heat exchanger is fluidly coupled to a heater by its inlet and outlet so that the temperature of the heating fluid for warming the infusate is maintained at a predetermined temperature.一種熱交換器具有一多管腔導管,該多管腔導管之一端連接至一供給配件且另一端連接至一返回配件。該導管具有一中央管腔、一圍繞該中央管腔之中間管腔,及一圍繞該中間管腔之外部管腔。該供給配件具有一入口、一出口及一近端口,一注入物經由該近端口輸入至該熱交換器。該供給配件組構將其入口連接至該中央管腔,其出口連接至該外部管腔,且其近端口連接至該導管之該中間管腔。該返回配件組構成在該導管之該中央管腔與該外部管腔之間建立一通過通路,使得一經由該供給配件饋入至該中央管腔之加熱流體經由該外部管腔返回至該供給配件。該返回配件進一步具有一組構成連接至該導管之該中央管腔之遠端口,使得饋入至該供給配件之該近端口之該注入物可在穿過該導管之該中央管腔之後自該返回配件之該遠端口輸出。由於該注入物沿該熱交換器穿行,故其由沿該中央管腔流動之加熱流體加熱,且亦由沿該導管之該外部管腔流動之經再導引之加熱流體加熱。該熱交換器藉由其入口及出口流體連通地耦接至一加熱器,使得用於使該注入物溫熱之該加熱流體之溫度保持為一預定溫度。2‧‧‧熱交換器4‧‧‧導管4a‧‧‧近端/中央管腔4b‧‧‧
