Cold receptors are specialized nerve endings in the skin that detect changes in temperature, specifically cold sensations. These receptors are part of the nervous system and respond to temperatures below the body's normal range, typically around 20°C (68°F) or lower. They help the body sense and react to cold environments, contributing to the overall perception of temperature. When cold receptors are activated, they send signals to the brain, which interprets these signals as a sensation of cold. This process is essential for maintaining homeostasis, as it prompts the body to take actions like seeking warmth or adjusting clothing to prevent hypothermia.