Here is an experiment I just tried last week. It's one way you can sterilize medical equipment. Basically you wrap your tools up in the special blue paper and then use the tape to secure it. Put it in the oven and when the temperature has reached the point where the items are sterilized-- the tap changes color. You can easily see this in the second picture where the tape that originally looked like plain masking tape now has gray lines across it. When the experiment was over, my mother had four sterilized forks. :)
Shiloh