From the temperature of local skin, heat or cold syndrome can be differentiated, and the condition of blood circulation of the sick limb can be known. A hot swelling generally indicates a new trauma or heat stasis or infection of local part; and a clod swelling indicates a cold disease. If the distal part of the traumatic limb is cold and numb, and pulsation of the artery declines or disappears, this means a disturbance of blood circulation. Generally, it is advisable for a person to feel the skin temperature with his dorsum of hand.