The immune system is the body's defense against infectious organisms and other invaders. Through a series of steps called the immune response, the immune system attacks organisms and substances that invade body systems and cause disease.
When the humidity is high it feels oppressive outside because sweat doesn't evaporate and provide cooling. When the humidity is low you feel cooler, but your skin dries out and you get dehydrated more easily because more moisture is being evaporated from your body. The same thing applies to crops in high and low humidity. A high water vapor content is necessary to produce clouds and precipitation.
Finally, they learn how exposure to extreme environment conditions -- such as high altitude -- can affect the body's ability to maintain homeostasis. Objectives. Understand how the human body regulates temperature and how a fever fights infection; Explore ways in which the human body self-regulates to maintain homeostasis