Yawning is commonly linked to sleepiness or boredom, but it doesn’t always signal the need for rest. Yawning may serve as a reflex that helps increase alertness and wakefulness. It can raise your heart rate and release hormones that enhance focus, making it easier to stay awake during monotonous activities like driving or watching TV. Additionally, yawning helps cool the brain, as the deep inhalation of air lowers its temperature. Yawning can also be a way for the body to adjust its awareness—like yawning before bed, which may indicate that the body is preparing for sleep.