Not really. Armor acts as a heat-sink, and as long as it has a mirror polish it will work to reflect light much more than a satin or matte finish. The kit also has pretty good circulation if built right. Heat is a problem in armor, but not nearly as much as many think. I live in Florida, and even then when I have heavy kit on I don't start to suffer any negative symptoms from heat until after prolonged intense physical activity, when I haven't been hydrating properly, and when there is no breeze.