Sleeping with a fan running all night can feel like the perfect solution during warm weather, but waking up with a stiff or uncomfortable neck can make people wonder whether the fan is responsible. The fan itself does not normally injure the neck, but continuously blowing cool air toward the body can contribute to discomfort in some people, especially when combined with an awkward sleeping position.

When cool air blows directly across the neck and shoulders for hours, some sleepers may wake feeling unusually stiff or tense. Staying in one position for a long period can already leave muscles sore, and a cold bedroom or constant airflow may make that sensation more noticeable. The problem can be especially uncomfortable when a pillow fails to keep the head and neck properly supported.

Fans can also circulate dust, pollen, and other particles around a bedroom. For people sensitive to them, this may contribute to a dry nose, irritated throat, congestion, or watery eyes. Constant airflow directed toward the face can also dry the mouth and nasal passages overnight.

That doesn’t mean sleeping with a fan is inherently dangerous. Many people use one every night without experiencing problems. Pointing it away from the face and neck, using a lower setting, keeping the fan clean, and maintaining a comfortable room temperature can reduce unwanted dryness and discomfort while still providing cooling airflow.

If someone wakes with a dramatically swollen neck, severe pain, breathing or swallowing difficulty, fever, or swelling that continues to increase, however, it shouldn’t simply be blamed on sleeping beside a fan. Those symptoms can have other causes and should be medically evaluated. For ordinary morning stiffness, adjusting airflow, pillow position, and sleeping posture may be all that’s needed.