Eons ago, back when evading predators and foraging for food were humankind’s main activities, stress was essential to survival. The body’s fight-or-flight response to stress in the face of danger set off a chain reaction of physiological changes, priming the body for action and increasing the likelihood of escaping physical harm.

We’re typically concerned about dehydration during summer’s simmering months. But winter has a unique set of characteristics that make us particularly susceptible to dry skin. Because of the cooler temperatures, we’re less apt to feel thirsty and drink a proper amount of water, even if our skin is in dire need. We’re also less likely to notice the effects of the sun on a cool day, which can lead to overexposure of UV rays. And the arid heat of furnaces warming the indoors may also take its toll and dry out already taxed skin.

Eyes may be the mirrors to the soul, but they are also the mirrors of the body, reflecting stress levels, overall health, lifestyle, and, of course, age. When life is good — you’re eating well and getting sufficient rest, plenty of exercise — your eyes sparkle. But when the going gets tough, eyes show it, and it’s not pretty — puffiness and dark circles appear, and wrinkles seem to deepen.

Your complexion can reveal a lot more about your health than simply whether you are dehydrated or have spent too much time in the sun. In fact, how your skin looks can be a strong indication of whether you’re making the best food choices for your body. That’s because food allergies and intolerances can compromise the digestive and immune systems, giving rise to acne, eczema, rosacea, and other bothersome skin conditions.