"The Science Behind Nipple Hardening in Cold Weather"

Exposure to cold temperatures triggers the sympathetic nervous system, causing specialized nerve cells to contract muscles and erect nipples, a process that helps retain heat. This response, also responsible for goose bumps, is a remnant of our evolutionary past when body hair insulation was crucial. Nipples can also become erect due to sexual arousal, hormonal changes, and emotional responses. While usually a normal bodily reaction, persistent or extreme nipple erections unrelated to temperature or excitement may indicate a health issue.