Memory foam usually needs to be hand-washed, as machine washing can make it deteriorate. However, memory foam often has hypoallergenic features that repel mildew, dust mites, and other allergens; meaning it doesn’t need to be cleaned as frequently as other types of pillow fillings.
Walking at a brisk pace can burn almost as many calories as jogging the same distance.
Yawning is just a sign of tiredness.
Yawning is typically thought of as an indicator of fatigue, but in reality the real causes of yawning remain a mystery even after continued scientific scrutiny.
One theory is that yawning facilitates low oxygen levels in the lungs, but this has largely been discredited after observations of foetal yawning (there’s no oxygen in the womb).
Another mystery of yawning is how contagious it can be. Studies have shown that yawning can trigger off a contagious response in up to 60% of people who are exposed. It even affects dogs!
Some scientists have proposed contagious yawning may have helped our ancestors to coordinate times of activity and rest. Another recent experiment has suggested that yawning may be an attempt to cool the brain down.