The common cold causes congestion, sore throat, and sneezing. Both colds and flu can cause cough, headache, and chest discomfort.
Cold or flu complications are usually minor and include bronchitis, sinus pressure, and sinus infection. Influenza (aka the Flu) is a contagious viral infection of the respiratory tract. It is more likely to cause high fever, body aches, fatigue, and weakness when compared to common colds though. Complications include bronchitis and pneumonia. Flu is spread by inhaling droplets in the air containing the flu virus, sharing drinks or eating utensils, or handling items touched by a person infected with the flu after gaining entry through the eyes, mouth, or nose. Hand washing is an important prevention method of both colds and flu. Symptoms begin 1-4 days after infection with the flu virus. Those most susceptible include pregnant women, infants, elderly, and those with chronic disease such as diabetes, heart disease, and HIV.
Fever is a symptom, not a disease on its own. It is the body's reaction to infection and illness and helps the body fight against invading organisms. Most healthy children and adults can tolerate a fever of 103-104 °F for short periods without problems. Viral infections (cold/flu) and bacterial infections (urinary tract infections/pneumonia) often cause a fever. Fever that begins after travel in other countries needs to be evaluated by a doctor as this allows exposure to other diseases. Frequent/recurring fever (3 or more times in 6 months 7 days apart/fever 48 hours apart) should also be evaluated by a doctor as well.