Why do our hands sting when we hit golf balls on cold days? It has to do with the way the body attempts to stay warm, says Ralph Simpson, Golf Digest Professional Advisor on health and fitness. The body, says Simpson, would rather protect vital organs and conserve its core temperature, so secondary muscles and tissues receive less blood and oxygen. Consequently, when we're cold, vessels in our extremities constrict, reducing blood flow to the skin and decreasing heat loss. A lack of blood in the hands causes the pain we feel when we hit a shot."Just like a cold rubber band easily tears," says Simpson, "muscles that receive less blood and oxygen are more susceptible to strains and tears. They allow a smaller range of motion for joints, which impairs coordination, strength and power."Simpson says the best way to keep blood pumping and improve coordination when you play is to activate your muscles. Take 10 minutes to do jumping jacks, running in place and high knee kicks before heading to the range or teeing off. If you wait more than 15 minutes between shots, pace back and forth and jump around. Injury prevention will outweigh any embarrassment.