Heat sensitive thermochromic paper changes colour as the temperature rises, even from the heat of your hand.
A novel way to investigate temperature, insulation, and body temperature.
The paper is supplied in four colours blue/white, purple/pink, pink/white and green/yellow.

Physics School Lab Equipment Suppliers in India
 

Ltekonline are the manufacturers of Heat Sensitive Paper Heat Lab used to demonstrate engineering principles in Engineering Colleges, Engineering Schools and Physics Lab Experiments for Engineering Teaching Lab in Universities