Waterproof stick on thermometer?

[pelipen]

Any recommendations for a stick-on aquarium type thermometer which is waterproof? I have a couple, but after having a wet shirt cover it for a week in a swamp cooler, all the temperature indicators turned grey, and it's pretty hard to tell what the temperature is.
I think it's ruined. Since it's mostly done fermenting, I don't care, plus they're cheap, but I want one that will be useful more than once.

This is what I'm talking about:

 

[certaut]

cover it with clear packing tape

 

[thedartedash]

cover it with clear packing tape

+1!

 

[zeekage]

Also leave it for a while to dry. i had the same thing happen and eventually all the numbers faded and it seems to read properly again. It must have been a few days at least before it worked again.

I 2nd the clear packing tape. that will stand up to a wet tshirt or a water bath for a short time. I do notice the clear packing tape starts to let go eventually when it's wet so be gentle with it.