The Trans Catalina Trail can be extremely hot in the summer months. If you are going to be hiking in the summer and are worried about the heat and difficulty of the trail. I would highly recommend looking into gear haul services for the more strenuous portions of the trail. All your backpacking gear is delivered directly to your campsite and you can bring extra water/food/drinks/firewood. 310-913-9036 with Catalina Backcountry