The pressure of a gas or liquid can be increased by decreasing its volume. The container walls and anything inside the container experience twice the force. The pressure increases because the same number of molecules are taking up half the volume and are colliding twice as often. Pressure and Temperature Pressure of an ideal gas is directly proportional to temperature, increasing at the same rate as temperature increases. Doubling the temperature doubles the pressure.
Molecules travel faster at higher temperatures, so they collide with other objects more frequently.