The skin can be checked for three main factors: color, temperature, and condition. Color refers to the overall pigmentation of the skin, which can indicate certain health conditions. Temperature refers to whether the skin feels warm or cool to the touch, which can also provide information about circulation and overall health. Lastly, condition refers to the overall appearance and texture of the skin, including any abnormalities, rashes, or lesions. By checking these three factors, one can gain insight into the health and well-being of an individual's skin.