System and method for leak detection in external cooling pad

1. A heat exchange pad, comprising:

an outer envelope configured for placement against the skin of a patient to exchange heat therewith and including:

an outer layer made of a high dielectric material such that any electrical discharge in the pad is effectively blocked from passing through the outer layer to the patient;

an inner layer; and

a middle layer sandwiched between the inner and layers and made of a relatively electrically conductive material, the middle layer being electrically connected to a control system associated with the pad.

2. The pad of claim 1 , wherein the layers are laminated together.

3. The pad of claim 1 , wherein in the event of a rupture in the inner layer, coolant in the pad contacts the middle layer to establish a change in impedance that is sensed by the control system.

4. The pad of claim 3 , wherein an impedance between the middle layer and the coolant is used as an indication as to whether a leak exists.

5. The pad of claim 4 , wherein a drop in impedance indicates a leak in the inner layer.

6. The pad of claim 1 , wherein the inner layer is made of the same material as the outer layer.

7. The pad of claim 1 , wherein the middle layer is made of foil.

8. The pad of claim 1 , wherein the middle layer is made of plastic impregnated with conductive material.

9. A method for providing an alarm indicating an impending loss of fluid integrity of a heat exchange pad engageable with the exterior of a patient before fluid in the pad leaks out of the pad onto the patient, comprising:

receiving a signal from the pad representing an impedance; and

if the signal satisfies a leakage threshold, activating an alarm.

10. The method of claim 9 , wherein the impedance at least in part is related to a middle conductive layer sandwiched between two non-conductive layers of an envelope of the pad.