The high pressure and the low temperatures are the two conditions, which can restrict the effectiveness of the kinetic-molecular theory in illustrating the behavior of the gas.
At high pressures or at low temperatures, the real gases deviate substantially from the ideal gas behavior. Due to this, the two conventions of the kinetic molecular theory, where gas particles hold an insignificant fraction of the entire volume of the gas, and the force of attraction among the molecules of gas is zero would become uncertain.
