You may have heard that putting an activated glow stick in the freezer or deep-freeze will stop the ‘glow’ effect and let you save the glow stick for when you need it next.
Can this be true?!?
Why, yes! It is true!
Since the glowing effect of a glow stick is a luminescent chemical reaction, temperature has a direct effect on glow chemical products. Cooling or freezing a chemical reaction causes the effects to slow, by heating it, this increases and speeds up the reaction. By placing an activated glow stick in the freezer, you are freezing the internal liquids and in turn slowing the chemical reaction. By completely freezing a glow stick, you are effectively shutting ‘off’ the glow effect. This will work for any chemi-luminescent product.
On the alternate side, having a glow stick in a hot environment will cause the chemical reaction to increase resulting in a much brighter glow effect for a reduced duration. So by re-heating a glow stick, you are reactivating the chemical reaction and starting the glow effect again. Keep in mind that this can reduce the overall duration of the glow stick slightly.
Important Safety Note: Do not place a frozen Glow Stick in the microwave to defrost it! Since a glow stick is a sealed plastic tube with internal chemical liquids, placing it in a microwave can cause it to melt or even explode. It is always recommended to under warm tap water to defrost it.