Jorge GranadosPerforming loaded work in hot ambient environments is a common challenge for military soldiers. Blood delivery to the skeletal muscles in the attempt to maintain body temperature within certain boundaries place simultaneous demands on the volume of blood being pumped by the heart, also known as cardiac output (Q). Competition between these processes leads to significant cardiovascular strain and reduced blood flow to the intestinal tract. This results in increased risk of exertiona...

Read the weekly text article "The Invisible Death Ray" by John Seawright. "We’ve all seen it; the vicious collision that leaves a football wide receiver writhing in apparent pain; his strenuous, assisted walk to the locker room; and his eventual return to rejoin his team on the sideline with the accompanying statement from the sideline reporter, “The x-rays are negative.”