mosquitoes and when the fever reached its peak after three to four days they were given various experimental treatments. During one Malaria experiment at the University of Minnesota, twelve CPS men underwent tests to determine the recovery period for those infected with malaria. This research documented the debilitating effects of the disease and the amount of time required for a complete recovery. Cold and pneumonia CPS men participated in tests in Pinehurst, North Carolina and Gatlinburg, Tennessee during which they drank throat washings contaminated with soldiers' colds and pneumonia. Through this experiment, researchers with the Commission on Acute Respiratory Disease came to the conclusion that colds and some types of pneumonia are caused by a virus rather than bacteria. Starvation To study the effects of diet and nutrition, Ancel Keys of the University of Minnesota Laboratory of Physiological Hygiene placed 36 conscientious objectors on a controlled diet. Later known as the Minnesota Starvation Experiment, the study was split into three parts: a control period, a semi-starvation period, and a refeeding period. For three months the subjects were given a normal daily diet depending on the weight. This was followed by six months of a diet, fewer calories than provided by the famine diet experienced by the civilian population in wartime Europe. The results showed an average of 24% loss in body weight, 40% loss in resting metabolism, decreased heart size, decreased blood pressure, 30% decrease in lung capacity, and other serious effects. The research not only documented the men's ability to maintain physical output, but also the psychological effects of the restrictive calorie diet such as introversion, lethargy, irritability and severe depression. The study then followed the men's long recovery as they returned to a normal diet and regained the weight lost during the experimentation. The study provided valuable insights into hunger and starvation and the results were made available to all major relief agencies concerned with postwar food and nutrition problems, helping to inspire the Marshall Plan. It became the most widely publicized of any of the experiments on COs and the results continue to be beneficial to the study of famine and anorexia. Other experiments A number of other experiments were done to help test soldiers' abilities to survive in the extreme conditions the war presented. These tests included exposure to excessively high altitudes, cold, and heat. For example, to test the effects of extreme heat on soldiers,