IIN to feel how hot the water is before stepping into the shower?

Google image it. I haven't checked but they probably have a pic. I first saw one in high school. I was in an elective architecture class and we went on a field trip to this rich guys mansion to study the architecture. He invented a surge protector for some military application. Anyway, we were touring the house and he took us to the bathroom where he showed off his "toe tester spout" in the ornately tiled shower. You could tell he wanted to impress us. Ha