Why are high temperatures dangerous?

the body of an animal or human has a certain constant temperature for example 98 degrees Fahrenheit for humans... and it needs this temp to work properly. DNA is 2 strands of important cells that "zip" together and form its unique shape. if a fever gets too high, it can "unzip" your DNA, your body cant function right and it goes into shock. high temperatures destroy cells that contain info on how to work and live