Recently cut my hair rather short (about an inch) and kept getting facial flushes and occasionally chills. It's been something over a week, and yesterday did not notice, though is now growing out again too, but is it possible my head just had to relearn how to regulate body heat given the new circumstances?

While the common belief that your body heat escapes through the head isn't necessarily true, in your case it could be the reason why you were getting chills. Since areas above the chest are the most uncovered part of your body when going out on a cold day, people usually think it's the head that releases all the heat. That is correct if the rest of you is covered up, since heat has no where else to go but out of the head. If someone was wearing a hat, mask, heavy jacket and shorts, their body heat would be released out the legs. Since you were used to having longer hair but cut it off, the skin on your head is exposed, giving more places where heat can escape.

While the common belief that your body heat escapes through the head isn't necessarily true, in your case it could be the reason why you were getting chills. Since areas above the chest are the most uncovered part of your body when going out on a cold day, people usually think it's the head that releases all the heat. That is correct if the rest of you is covered up, since heat has no where else to go but out of the head. If someone was wearing a hat, mask, heavy jacket and shorts, their body heat would be released out the legs. Since you were used to having longer hair but cut it off, the skin on your head is exposed, giving more places where heat can escape.

 

Covering a body part doen't prevent heat escaping it, it just slows it down.