Some patients with Sjogren's have difficulty sweating due to the obstruction of their sweat glands from the overwhelming prevalence of B lymphocytes. A Sjogren patient's athletic performance and energy levels can be greatly impacted by the inability to sweat, which can be explained by a principle in physics: a phase change from liquid to vapor and water's high heat of vaporization.
Due to water's very high heat of vaporization, humans can release a significant amount of heat from their bodies, which is produced by metabolism and working muscles, during exercise. This can be understood by the equation for a phase change, Q=mL (heat=mass*latent heat of vaporization). The large amount of heat that the evaporation of sweat can release allows our bodies to cool in temperature giving us the capacity to tolerate what would otherwise be potentially dangerous increases in body temperature.
Especially in Venus' case, Sjogren patients who are physically active should look into how to best treat their condition. Attempting strenuous activity in high temperatures without the ability to release the body's heat through sweat has a high risk for heat-related illnesses such as heat exhaustion or death.- post written by Michelle White