higer temp= higher bottle pressure... which means harder shot and more forceful purge.. thats why a bottle heater is made, to raise temp and pressure of bottle. nitrous is alot more effective at 900-1200 psi. where as at 500 psi you will hardly make a difference. aslo , if you have a heater and you spray in cold weather(like 30 degrees) your car will run its ass off. cold air is less dense and helps the functionality of the motor