Rosy cheeks occur as a result of blood vessels widening near the surface of the skin. In many cases, the body will react like this for benign reasons, such as trying to warm the skin up in cold conditions.

Why does my face get red when it's cold?

Cheeks flushing or vasoconstriction take place when your blood vessels narrow to reduce blood flow near the body's surface. Sometimes the blood vessels dilate and burst, which causes redness.

Can cold weather cause rosy cheeks?

Winter weather can also trigger rosacea flare-ups. Dry, cold air can set off redness in the cheeks, nose, and forehead, similar to facial flushing. If not addressed quickly, the symptoms can get progressively worse, causing small yet painful papules and pustules on the face.