Should I wash my meat thermometer?

I was cleaning up the kitchen after dinner the other night and came to the food thermometer left on the counter.  Doug had made hamburgers and, as always, declared them done when his digital thermometer indicated that they were at least 160 F on the inside.  My question to him was, “Do I need to wash the thermometer before I put it away?”  Water is bad for the digital mechanism, but do I need to worry about potentially cross contaminating foods if I don’t wash it?  What if I’m cooking hamburger and chicken on the grill … do I need to use two separate thermometers?  I imagine that the E. coli won’t survive on the metal surface for long, but I’m not a microbiologist.  Food safety isn’t really simple.

Find helpful information about this from the factsheet on grilling published by iFSN.