I really tried, but I couldn't understand what to do. I thought I had to match the colour of the material with the temperature gauge, but that didn't work. The few times that I managed to make a watch, I had no idea what I did right. I see other participants are complaining about controlling the temperature. As you have generously provided the source code, it looks like you've put the temperature controlling part into the Update loop. You should only put the Input part into that loop, the actual logic should be in the FixedUpdate loop instead.
I liked the music.
For some reason, the first "BEEEP" is a lot louder than the other ones. I guess multiple ones are playing at once by accident, but I couldn't find anything in the programming that would cause that.