Eye color for a plausible argument stating that some eyes can or do change, based on chemical reactions and hormonal changes within the body. Studies on Caucasian twins, both fraternal and identical, have shown that eye color over time can be subject to change, and major demelanization of the iris may also be genetically determined. Most eye-color changes have been observed or reported in the Caucasian population with hazel and amber eyes. Carleton Coon created a chart by the original Martin scale. The numbering is reversed on the scale below in the (later) Martin–Schultz scale, which is (still) used in physical anthropology.
Thermoregulation in humans are impermeable to sweat and thus do not facilitate heat loss through evaporation can actually contribute to heat stress. Adjusting the human body temperature downward has been used therapeutically, in particular, as a method of stabilizing a body following trauma. It has been suggested that adjusting the A1 receptor of the hypothalamus may allow humans to enter a hibernation-like state of reduced body temperature, which could be useful for applications such as long-duration space flight. Humans output from 70 watts to 870 watts, depending on the amount of physical activity undertaken. Thermoregulation in humans As in other mammals, thermoregulation in