Termochronic indicator

This is an attachable indicator of temperature drop. The idea is to use termochronic filament which in my case changes color from green to yellow at arround 33 C. This allows you to watch the temperature drop in various condensers or coolers, without touching it all the time.
It could be especially useful if you have long running distillation processes ;-) and would like to minimize the amount of wasted cooling water.