Recent studies have shown that prolonged tension can weaken the body's ability to resist the invasion of germs, make people susceptible to colds, and form so-called cold constitutions. Scientists at the Salisbury Cold Research Institute in the UK isolated 394 volunteer testers from the outside world for 9 days. The next day, they dropped a few drops of colorless and transparent liquid into the tester's nose. They perform daily checks to record cough, asthma, and runny noses, and most of the infections are known early through blood tests. These results are the same as the psychological tests performed on these subjects before isolation. This shows that the higher the degree of stress, the greater the possibility that the cold virus will work. Research results show that 47% of the participants in the trial became sick due to their increased stress, and only 25% of the non-stressed people became sick.