Water warms you up another way as well. It helps power your metabolism, and a sluggish metabolism translates into less overall body heat. Aim for the requisite eight glasses a day at a minimum, recommended Maggie Moon, but always drink more before and after workouts. RELATED : 12 Reasons Dehydration Is Bad for Your Body You don't consume enough vitamin B12 This nutrient found only in animal products plays big role in preventing big chills. The body needs vitamin B12 to make red blood cells, which carry oxygen through your system.