Yawning may be due to overheating of the brain

For a long time, many people still believe that yawning is the act of bringing new fresh oxygen to the brain, helping us to be awake. However, studies cannot show an increase in blood oxygen after yawning.

Now, Austrian scientists have discovered that yawning is actually a way to help the body control the temperature of the brain to increase alertness and mental ability.

People tend to yawn when tired, stressed or lacking in stimulation - factors that can lead to changes in the temperature of the brain. Researchers from the University of Vienna (Austria) have tested whether air temperature can affect our yawning level.

Yawning helps people control the temperature of the brain to enhance alertness.(Photo: Thinkstock)

The research team gave Vienna-based pedestrians photos of people yawning to trigger yawning. They conducted tests during the winter and summer months to see how the air temperature affected the yawning frequency.

When compared to a similar US study, conducted in Arizona, where the climate is dry, experts found, people in Vienna yawned more in the summer, while people in Arizona were the opposite, yawning more in winter.

The team concluded that yawning is most likely when the temperature is around 20 degrees Celsius . The frequency of yawning decreases when the temperature is about 37 degrees Celsius in the summer in Arizona and falls sharply to the freezing point in Vienna in the winter.

According to Dr. Jorg Massen, head of the Austrian team, yawning seems to be useless when the air temperature is as high as the body or at freezing.

This has confirmed the results of a previous study that people yawned after their body temperature increased . Meanwhile, the age, gender, and sleep the previous night did not have much impact on our yawning action.