Colds primarily occur among populations with diminished immune functions, such as infants and the elderly. Since infants do not develop their own resistance until the age of six, they tend to catch colds more frequently. It's also common for someone to catch a cold again soon after recovering if they get chilled. Thus, this group typically has particularly low immune function, leading to frequent colds. Therefore, we recommend that such patients should exercise regularly and consume foods high in vitamins. It is also advisable for them to engage in physical activities within their capacity. With long-term exercise, their immune strength can be significantly enhanced, thereby greatly reducing the frequency of colds. It's also wise to avoid going out to public places during the peak cold season whenever possible.