Cold air causes bronchospasm or constriction of the bronchial tubes and places a higher work demand on the heart. For kids and adults with asthma, being prepared for that physiologic effect is key. Use an inhaler or give a breathing treatment with a nebulizer before going outdoors. Wearing a ski mask or scarf over the mouth and nose can help to warm the air to some extent. Limit time exposure in cold air to 20 or 30-minute periods. Take frequent breaks indoors to limit exposure. If your child begins to have difficulty breathing and does not respond to prescribed medication at home, seek medical attention at a certified urgent care center or emergency department.