The most common cause of vascular obstruction is a blood clot, also known as a DVT. This type of vascular problem usually occurs in one leg (not both), and leads to swelling of the soft tissues throughout the foot and ankle. The swelling can also extend further up the leg.
The hypothalamus is a part of your brain that controls body temperature. When you exercise, your body temperature increases, causing the hypothalamus to signal the brainstem to further increase your heart rate.
Heat Stress. Heat stress can increase your heart rate, and, if severe and prolonged, can cause significant health problems. According to the Canadian Centre for Occupational Health and Safety, in moderately hot environments, your body vents heat by increasing the heart rate and pumping more blood to the surface.