I wish to find a pigment that can indicate when a battery contact is getting too hot, and all the thermochromic pigments from hobby stores change color below body temperature, at 31 °C is the highest I found.
What kinds of thermochromic pigment can be used for electronic components, that would change color at 40–50 °C / 120–140 °F?
The best thing would be easily obtainable and would give an rough indication of temperature transitions from 30 to 55 °C