The operative word is "need"......you will find successful breeders that do cool and ones that don't cool.........for the most part all rhacs need a rest period between breeding seasons to gather their resources and health back up to 100%. So, 1st year females do not need to be cooled until after they have laid a bunch of clutches at which point lower temps into the 60s at night and restrict their light to 8-10 hours per day for a couple of months.