You don't call off work when the temperature drops, so why settle for just any old fleece that's going to lay down on the job. All fleece isn't created equal, and we prove it with the PolarForce Hybrid Fleece Jacket that's going to keep you warm and take whatever abuse you throw at it. The entire PolarForce Collection was designed for flexibility, warmth and maximum functionality. Excuses are for the other guys - outperform with PolarForce. Sizing Instructions: For the most accurate fit, take your measurements over the base layer of clothing you intend to wear with this RefrigiWear gear (such as thermal underwear, jeans or a sweatshirt) and refer to the size chart for this product.