the top of the sleeve 42 is completely blocked with the following exception primary coolant inlet and outlet conduits 52 54 extend through the elements 48 50 of the closure it being understood that the conduits 52 54 are connected to respective tubes such as iv tubes that lead to the catheter or pad in the non limiting embodiment shown each conduit 52 54 includes a respective hollow metal fitting 56 that extends through the upper element 50 of the closure and a respective hollow plastic fitting 58 that is engaged with the metal fitting 56 to connect the metal fitting 56 with the upper tubular portion of the conduit which upper tubular portion can be plastic respective metal tubes 60 are engaged with the metal fittings 56 and depend downwarldly through the lower closure element 48 into the sleeve 42 where they meet opposed ends of a metal or high thermoplastic coil 62 a plastic handle 64 with opposed gripping ears 66 has hollow legs 68 70 configured to receive the conduits 52 54 with the conduits 52 54 extending completely through the handle 64 each leg 68 70 rests on the top of the lower element 48 of the closure as shown and is fused to the upper and or lower closure element 50 48 accordingly the primary heat transfer element 22 including the coil 62 sleeve 42 closure elements 48 50 and handle 64 are supplied to the end user as a sealed unitary structure it may now be appreciated that owing to the use of plastic fittings 58 to engage metal.