Here's why:
* Hair is a poor conductor of heat: Hair is made of keratin, a protein that doesn't conduct heat very well. This means that even if the surface of dark hair absorbs more sunlight, the heat won't transfer deeply into the hair shaft.
* The amount of heat absorbed is small: The amount of sunlight that hair absorbs is relatively small compared to the rest of the body.
* Other factors influence body temperature: Body temperature is primarily regulated by internal processes like sweating and blood flow, not by the color of your hair.
In conclusion, while dark hair may absorb slightly more heat than light hair, the difference is too small to have any significant impact on your body temperature.