does it specify anywhere that kes also refers to body hair?

The main target of Gurmat is to understand the Hukam of Akal Purkh and try to become Sachyaar /Truthfull person.
ਹੁਕਮਿ ਰਜਾਈ ਚਲਣਾ ਨਾਨਕ ਲਿਖਿਆ ਨਾਲਿ ॥੧॥ Jap – 1
At the same time we must understand that whatever we do, we should be ready to bear the consequences.
Akal Purkh have created all the body parts with specific purposes. If we play with any of the body parts then we may suffer in the long run.
ਇਹੁ ਸਰੀਰੁ ਸਭੁ ਧਰਮੁ ਹੈ ਜਿਸੁ ਅੰਦਰਿ ਸਚੇ ਕੀ ਵਿਚਿ ਜੋਤਿ ॥ – 309
This refers to not only the hair at the head but also at all the body parts
While fiddling with the hair at any part of the body, we disturbing the equilibrium of the skin.