Just using a LOT of water is a bad idea (unless you eat a good amount, with salt and other nutrients around that time). Because as we all know, this can lead to hyponatremia (at the risk of stating the obvious: you sweat out a lot of salt with the water you lose. Only replacing the water dilutes your blood (serum).
As altitude  increases, the air becomes less dense because of the smaller amount  of air above that altitude. There is a corresponding decrease in  pressure with an increase in altitude. Eventually you reach a point  without air, and the pressure decreases to zero. That is space. + 91 others found this useful.
In the troposphere, temperatures decrease as the altitude increases as it loses heat emitted from the surface of the Earth. In the stratosphere, the temperature increases with increasing altitude as the amount of ozone-absorbing ultraviolet rays increases. In the mesosphere, temperatures decrease as altitude increases and can reach -194 degrees Fahrenheit. By contrast, temperatures in the thermosphere can reach over 2,700 degrees Fahrenheit.Learn more about Atmosphere.