Because when our body temperature increases, we can basically damage our proteins, our enzymes found in the body. Now ironically, this is also a mechanism by which our body kills off bacterial cells. So when we're sick, the mechanism by which our body kills off the bacterial cells is by increasing the temperature of our body. This basically causes the proteins in the bacterial cells to basically denature and that decreases the activity and functionality of our enzymes found in bacterial cells. Now, let's move on to our acidity level. So how exactly does the PH or the concentration of hydrogen ions affects our functionality and activity of proteins of our enzyme?