The technician will teach your child a few different ways of breathing. First, your child’s baseline lung function will be tested. During this part your child will blow into a tube, using effort as if blowing out birthday candles. Next your child will breathe cold air through a special breathing circuit using a mouthpiece similar to what a scuba diver uses. The air will not feel cold on your child’s throat or mouth. After breathing in the cold air your child will repeat the first set of breathing tests to check for a change with the cold air. Your child will then be given a bronchodilator (medicine that helps open the small airways in the lungs). This medicine is given either as an inhaler or a nebulizer treatment. Some children may notice a faster heart rate for a short time after taking the medicine. The technician will then have your child repeat the first breathing test to check for any change with the medicine.