This is certainly not recommended but was curious to see how my deep pour resin copes with hot temperatures. 3L resin in single pour up to about 5cm (2”) in 33C (91F) and after two days it turned out perfect. Only used some cheap cookie as I was prepared this might fail. Used transparent so i can see if there are any signs of exothermic reaction.
Resin did go up about 41C (106F) while curing. Controlling temperature while working with resin is one of the most important factors to get it right. I know in winter time I could have poured more and deeper but every resin has limits