Autumn is here, and even if you haven’t sat through six hours of traffic to visit Kenosha Pass to see the changing foliage (we don’t blame you), the season’s change is palpable — especially in our bodies. As temperatures drop, our bodies instinctively boost appetite, preparing for the colder months by craving heartier, carb-rich foods, according to the National Institutes of Health. Like a chipmunk storing seeds in its cheek pouches, this evolutionary survival mechanism helps build fat reserves for warmth and energy.

Plus, according to the Sleep Foundation, reduced daylight impacts melatonin production, the hormone that regulates sleep. With longer nights, our bodies produce more melatonin, which can leave us feeling more sluggish and tired than usual. Serotonin levels — crucial for mood regulation — may decline due to reduced sunlight, potentially leading to feelings of lethargy or sadness and even seasonal affective disorder.

Our immune systems also become more vulnerable during fall, as colder weather brings people indoors, increasing exposure to colds and flu. The Mayo Clinic says that reduced sunlight lowers Vitamin D levels, which further weakens the immune system, making us more susceptible to illness. As if that weren’t enough, the cooler, drier Colorado air takes its toll on our skin and hair, according to the Mayo Clinic — stripping moisture and leaving skin dry or flaky, especially for those prone to eczema or psoriasis.

Hair can also become brittle.