Came across this today, looks like it could be useful for immersed probes such as DS18B20s or thermistors. It is good to 120°C.http://www.adafruit.com/products/1020
Is there an issue with the exposed metal?
It's purpose is to isolate the wire covering from your liquid. Most folks don't allow the wire to get wet anyway but I suppose this could be another layer of protection.