Never seen it ice if that is what your talking about.
Where ONE of the problems comes in is with a colored product the dispersion agent that encases the pigment (like a gel tablet) at 44 degrees can kick the pigment out of suspension and the paint will spray dirty, you cannot strain out or mix back in unless heated to 175 degrees and a high speed disperser is used.
This does not normally happen but can happen if left in area where it gets cold and warmed up next day over a number of cycles.
Other issue with clears and activators cold- hot cycles will cause condensation to build inside of can and destroy the product especially if can has been used and you have air displacing the material.
In 20 years, I have never seen the epoxy activator go south except twice both were just at the 3 year mark and allowed to set in shop that every night they turned the heat off in both cases BUT yesterday someone with a year old activator left in an unstable shop did not dry when he used it, dried but very slow.