Warm fluids through peripheral lines. Warm fluids through a central line. Warm fluids through bladder irrigation. Even (my first time seeing this), warm fluids pumped through an anterior chest tube to be drained by a posterior chest tube. With the patient's core temp continuing to drop (turns out he really was cold and dead), the surgeons brought him up to the OR for bypass, but without success. Despite our best efforts, he'd been down for too long before being rescued, and didn't make it.
On a related note, performing chest compressions for 1.5 hours (even with lots of people cycling in and out) is tough exercise!