Since other particles are orbiting their own lines nearby, at a macroscopic level, this change in energy appears as an increase in pressure.[42] According to the ideal gas law, this results in an increase in temperature. Like ohmic heating, this process also becomes less efficient as the temperature increases, but is still capable of creating very high temperatures. When the frequency is deliberately set close to that of the ion circulation, this is known as ion-cyclotron resonance heating,[45] although this term was not widely used at the time.