Core body temperature?
Human beings have excellent system regulating body temperature (i.e. thermoregulation), compared to other animals. However, you may think why many people have suffered from heat stroke (i.e. illness due to high body temperature). The most important reason is that human being have excellent thermoregulation system. This statement must have a contradiction! You may think so, but this is true. To explain for the reason, I have to tell about “core body temperature”.
Human beings are one of animals, which can control body temperature constant, homeothermoc animals. At the same time, human beings are categorized as endothermic animals. Endothermic animals can keep temperature of core body higher (“core body temperature”) by heat production of the body. In general, endothermic animals have greater body size, and are not easily influenced by change in environmental temperature. On the contrary, homeothermic animals with smaller size of the body are affected by the environment. Thus, they are called as “ectothermic animals”.
However, when human beings are exposed to severe heat and/or sternously exercise in a hot environment, core body temperature increases. Most animals evacuate to cooler environment and/or stop exercising, preventing excess increase of core body temperature. But, how about human beings? We do exercise and work even in a hot environment. We have patience. The reason for the patience is that we sweat, a golden tool for thermoregulation in heat. Thermoregulation by sweating is achieved, when the sweat is evaporated to the air. The evaporation steals heat from the body, by which human beings can exercise and work even in an environmental temperature above core body temperature.
Limitation of sweating and heat stroke
Sweating is No.1 tool of thermoregulation in heat. However, it has limitation. When we are dehydrated, we loose water for sweating. Sweating needs energy. Even though we dring a lot of water, excess sweating results in a lack of sweating from the sweat galnds (fatigue of sweating). More important problem is humidity of environment and clothing. Sweat needs evaporation for thermoregulation, high humidity and/or clothing which prevents evaporation results in increase of core body temperature. Human beings might trust sweating to muc, which lead them heat stroke. However, it would not be practical to stop exercise and work in heat for the prevention of heat stroke.
Core body temperature monitoring
In an environemnt where people have risks of heat stroke, core body temperature monitoring could be an effective tool preventing heat stroke. However, there are some technical problems in the core body temperature monitoring. The core body is surrounded by the shell body (i.e. skin and underlined tissue), which are influenced by the environmental temperature. Therefore, core body temperature monitoring is needed to minimize the influence of the shell temperature.
Vitarate has developed a tool monitoring the tympanic temperature. The tympanic membrane has interesting anatomical characteristics, where many arterial branches to the brain run.
We use a sensor detecting infrared signal from the arteral brances, reflecting blood temperature to the brain. Moreover, the sensor does not touch the tympanic membrane, which allows safe and comfortable monitoring.