If we move to areas of higher or lower air pressure, we no longer function as well. The total mass of the atmosphere is about one millionth the mass of the Earth. Most of the atmosphere is located close to the Earth. The bottom 10 km is referred to as the troposphere. Airplanes fly just above this layer to avoid the weather.
Temperature drops rapidly with increasing height in the troposphere.
The next layer, the stratosphere, extends from 10 km to 50 km. The stratosphere is free of clouds. At the top of the stratosphere is a layer of ozone that protects us from the Sun's UV radiation. From about 50 km to 75 km lies the mesosphere. This is the part of the atmosphere where meteors tend to burn up.