A thermal chromic heat storing/releasing device includes a bag having an
enclosed space for containing a heat storing/releasing material, and the
heat storing/releasing material is a material that can store and release
heat and the heat storing/releasing material is contained in the bag. A
thermal chromic printed layer having at least a part disposed on the bag,
and the printed material is mixed with a thermal chromic dye, such that
the thermo chromic material will change the color of the printed layer
for a visual indication as the temperature rises or drops.