Regulate your core temperature! The Burton AK Helium Insulator Jacket is designed to control your body temperature with it's strategically designed PrimaLoftR insulation. When you are able to maintain your core body temperature without getting too hot or too cold, you perform better. If you're a lovely lady who just wants to have fun, you can't be restricted by your jacket paneling inserts at the underarms and sides are stretchy and highly breathable so you can be comfortable from the inside out. The Burton AK Helium Insulator Jacket is the instigator you need to get outdoors.