Yes the manual says that, but all the advice I received as well as information from the CLC folks led me to believe it was OK to proceed. And its a good thing too, I have not yet been able to get my work space over 62 F at any time. The epoxy has cured without issue with the overnight temp right at 50F. My normal working temp when I am mixing and applying the epoxy has been between 55F and 60F. I do however aim a shop light at the jugs of glue so they are considerably warmer than me! The glue flows freely and mixes well. After the 1st months bill arrived, I was no longer allowed to keep my glue out in the garage overnight!!!! A bit too much reaction from my lovely wife. Since that has happened I now let the garage temp drop into the low 40's if glue is not curing. I keep it at 50F if it is. I put the jugs of epoxy into a large plastic tote and bring them indoors with me when I am done working.