Charcoal is made by heating wood in the absence of air. The partly-burned wood is very hard and in the past it was used to stake out property boundaries. Medicinally, charcoal is thought to be a deodorant and disinfectant and is used for gas, poorly digested food in the stomach, septic diseases, and ulceration. In orthodox medicine, it is still used in the form of charcoal tablets for gas in the lower intestine. Carbo veg. is mainly given for exhaustion, weakness, and low vitality that follows an operation or illness. Shock, particularly after an operation, where the skin feels cold and the person looks pale but feels hot inside, is eased by this remedy. It is also given for lack of oxygenation in the tissues due to poor venous circulation. Symptoms include cold, bluish skin on the hands, feet, and face, bleeding varicose veins, or puffy, cold legs. There may be a cold tongue and breath, hoarseness, lack of coordination, and reduced energy. Digestive problems, regardless of diet, such as gas, indigestion, and heartburn are all helped by this remedy. Symptoms include a salty taste in the mouth, sour burping, and regurgitation of food. Carbo veg. is also used to alleviate headaches that occur in the morning, especially after overeating, and when the head feels heavy and hot, with nausea, dizziness, and a tendency to faint. This remedy is helpful for asthma and spasmodic coughing, as in whooping cough, with choking, gagging, and vomiting of mucus, and in bronchitis in the elderly.