Most bacteria prefer the perfect conditions that our bodies provide: nutritious, moist and warm. Conditions that can retard or kill bacteria are pH, high temperatures or even cold temperatures. The range of temperatures at which bacterial/microbial growth occurs are classified as psychrophiles (cold-loving), mesophiles(moderate-temperature-loving), and thermophiles(heat-loving).

Most people think of high temperatures as being the only way our body kills bacteria and give little thought to the other ways our body protects us. Experiencing chills- or finding your body temperature below normal- can be indicative of an infection from a type of bacteria/microorganism that thrive in low body temperatures, or as a protective measure, your body may reduce its temp- in order to kill the bacteria. The same goes for abnormal pH and really high fever. Other reasons-thyroid, environmental poison or toxins