I have edited the text in some places and added a couple of references that I found regarding the coats ability to keep the body warm . They show that if the enviromental temperature is above 32 C – panting is the MAIN cooler and radiation from the skin is less effective/important.
They also show that when the enviromental temperature goes above a certain temperature – the air trapped inside the coat is WARMER than the enviromental temperature. So again – the coat insulates and keeps the dog warm….they dont ”catch” cold air.
A couple of references is also added that shows that clipping the coat short on horses ,cattle and sheeps reduces the heat stress.