I have a tree growing behind my runs but is not big enough to cover my runs for protection from the sun. I have used a tarp to give shade. I have one of the blue tarps that is revirsable on one run and seems to not cool down the shaded part of the run like the gray thick tarps on my other runs. Should I add one of the gray tarps over the blue tarp for better protection? (If this makes any sence..LOL i have not clue what the name of the tarps are called)