Experts agree that the most important thing to remember when dressing for cold weather is choosing clothing that will help to regulate your body temperature appropriately. The best way to do this is to dress like an onion.

“Just like an onion, your winter clothing system should have many layers,’’ says Stefan Shapiro, an avid outdoors enthusiast and the Visitor Services Supervisor at the Appalachian Mountain Club’s Pinkham Notch Visitor Center.

Here’s how Shapiro layers for the winter: On the top, from the inside out, he starts with a synthetic or wool t-shirt, then a long sleeve base layer, a midweight thermal layer (like a synthetic fleece), a heavier weight thermal (like a puffy down jacket), and a rain and wind barrier (like a hard shell or rain jacket). On the bottom, he puts on a pair of quality long underwear, an insulated pant, and a waterproof hard shell. “I bring along multiple hats and gloves of differing weights for layering appropriately for my exertion level,’’ he says, and finally ends with high-quality, insulated and wicking socks and waterproof boots.

Remember: cotton is rotten in winter. “When cotton gets wet it actually works to cool you down, which is exactly what you don’t want,’’ Shapiro says. And remember to shed layers as you exert energy to avoid sweating, which can contribute to the potential of hypothermia.

Are you suffering from the umbles? Think: grumble, mumble, fumble, stumble, tumble. If so, it’s time to head indoors. As your body cools, blood goes to your core to protect your vital organs. You may become irritable. You lose the ability to think and speak clearly. Further along, fine motor skills, then gross motor skills are affected. “I would say that once you start to notice the umbles in yourself or a member of your group, you should either get back inside or take measures to warm your body up,’’ says Shapiro.

DIANE BAIR AND PAMELA WRIGHT