An increase in temperature does not cause an increase in blood pressure. Rising temperatures can cause a drop in blood pressure, and studies have shown that human blood pressure varies inversely with the temperature of the surrounding environment, with human blood pressure falling when the temperature rises and rising when the temperature falls. Also, studies have found that blood pressure is lowest in the summer and peaks in the winter. The reasons why blood pressure decreases due to higher temperatures are as follows: higher temperatures cause a decrease in vasodilator blood pressure, peripheral vasodilation, which changes the ratio of circulating blood volume to blood volume, resulting in a relative decrease in the amount of blood returned to the heart and a decrease in blood pressure. In addition, the response of the brain as well as the nervous system to temperature can also cause a drop in blood pressure.