Mr I is not uncovering anything, he is hanging out on LetsRun, and reporting what they turn up back to us. He is actually doing it in a more proportionate and less gleeful manner than they are over there, but that says more about LetsRun than about him.
Unfortunately, LR is not terribly interested in David Walliams, so you may be waiting some time for that evidence.
Phil must dissipate heat particularly well, potentially by having a larger surface area. Elephants do this by having particularly large ears. All of the bits of Phil that we can see are broadly in proportion, so we must assume that the hidden bits are the ones that are magnified.