Compression Heating of a Gas

An ideal gas, like air, or helium, will tend to heat up when it is compressed.  Unless measures are taken to cool the gas during the compression process, this can lead to a pretty large temperature increase for relatively modest pressure increases.  If we assume that no cooling takes place (adiabatic) it is easy to calculate the minimum temperature to which the gas is heated from the compression process alone.
The black line in this figure shows the minimum final temperature for air which is compressed adiabatically from 1 atmosphere, 70 degrees F to the gauge pressure shown on the x-axis.  

Note that automobile tires are usually only inflated to a pressure of around 30 psi (gauge), and at that compression the air leaving the compressor would be at almost 270 degrees F—well above the boiling temperature of water.  The figure only goes up to 100 psi (gauge) which is well within the range of many home air compressors, and at that pressure the temperature of the air would be getting close to 500 degrees F.  You might have noticed that most compressors have fins to provide some cooling to the gas and the compressor.  Compressors that are meant to operate nearly continuously usually also have fans or other measures to boost the cooling effect.
The total temperature rise depends on a gas property called the specific heat ratio which is denoted in this figure by the letter ‘k’.  For air, k is about 1.4 at room temperature.  The green line and the red line show the effect of compressive heating for other gases.  The green line is for monatomic gases like argon and helium for which k=1.667, and the red line is for butane for which k=1.091. 
The blue hash marks show the temperature rise for gases with various values of k between 1.091 and 1.667 at 40 psi (gauge).  The positions of carbon dioxide and propane are identified on the figure.