Epoxies, resins AND paint, including water base base coat, ALL have solvents in them.
basic science. refrigerating solvent products slows the evaporation rate of the solvents making them last longer.

it's a old bodyshop trick to refrigerate catalyzed paint. doing so almost always extends the cure rate allowing you to use it the next day.
most catalysts stop working at around 50*. this also works with almost any 2K product.