system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If sweating exists to control body temperature, why do sometimes people sweat from their feet or hands even though they are frozen cold?
gpt
If you've been doing physical work, your core temperature will increase, largely regardless of the outside temperature.  the natural response is to sweat to remove the excess heat.  since your head and feet (and hands) tend to have alot of capillaries near the surface of the skin, they tend to be much more efficient at removing excess body heat compared to the rest of the body, where blood vessels are deeper.