The ultimate engineering puzzle in a ski helmet is to create a product that keeps a rider warm on a frigid chairlift ride and cool during a heart-pounding mogul run. For 17 years, my team at SPIRIT has been refining the solution: advanced, user-controlled ventilation. It’s a delicate balance. The helmet must have a high-quality, insulated liner and plush earpads to provide a warm and comfortable base. But it also needs a system of large, effective vents to dump heat when exertion levels are high. Our solution is the "active ventilation" system. We engineer low-profile sliders or buttons that allow a rider to easily open and close vents with a gloved hand. The internal EPS foam is molded with deep channels that connect these vents, creating a true airflow system over the rider's head. This ability to instantly switch from warm insulation to cool ventilation is what makes a modern ski helmet so effective, and it’s a feature we have perfected.