[mdp2021]

It could be just rhetoric.

Nonetheless, there is some odd distortion there, with short circuits: the author relates «hair (or feathers)» to «heat transfer», but some argue that hair - that humans did in fact keep - is a protection against insects (to feel them as they "land"), before heat conservation; and on the same line the reason to leave the eastern African peri-rift was to escape insects (and other pests), which resist less in colder climates. The topmost human killers include, after mosquitoes, bugs and flies. Hair is not a protection from canids, but they remain near the top of human killers and cold climates reduce the threat coming from strays, and some types of clothing can offer some protection.

Clothing is not just a matter of heat conservation.