There’s a phenomenon called the Joule-Thomson (or JT) effect that causes the temperature of a gas to drop when its pressure is reduced in a valve or regulator. Low ambient temperatures increase the risk of freezing, but the driving factor is usually a combination of a high pressure cut and water content in the gas. Every 100 psi of pressure drop causes natural gas to lose 6-8° F, so even in very warm weather frozen equipment can still be a problem. The JT effect is happening inside the valve, so in a lot of cases insulation jackets can make the