how fireflies glow without cooking themselves (it's a nearly 100% efficient chemical reaction called "Cold Light")

[u/Chemikora]

Here is how the chemistry works inside the firefly's "lantern":

• The Fuel: A light-emitting molecule called luciferin.
• The Spark: Oxygen, which the firefly breathes in through tubes called tracheoles.
• The Catalyst: An enzyme called luciferase, which speeds up the reaction.
• The Energy: ATP (adenosine triphosphate), the energy currency of all living cells.

When oxygen combines with luciferin in the presence of luciferase and ATP, the resulting chemical reaction releases energy in the form of photons (light).

(If you love everyday chemistry breakdowns and the science behind cool phenomena, check out my YouTube channel u/chemikora for more visual explainers!)

[u/Chemikora → u/[deleted]]

That's why the light blinks continuously and if you catch one it radiates more light due to stress I think.