Colds, also known as upper respiratory tract infections, can develop in all seasons and there is no specific season. It usually occurs more often at the change of seasons, especially in winter and spring, when the change of seasons may lead to colds because children are not well adapted to the weather and their clothing is not properly adjusted. Symptoms of the nasopharynx, such as runny nose, sneezing, sore throat, fever, and possibly a cough, can often be present. This condition is mostly caused by viral infections, with a few caused by bacterial infections.