A cold, also commonly referred to as an upper respiratory tract infection, can generally be categorized into cold-natured and heat-natured types. If it occurs in winter, it is usually a cold-natured cold, and patients with this type are generally not recommended to eat watermelon.

On the other hand, a heat-natured cold in summer typically presents symptoms such as runny nose, nasal congestion, fever, headache, sore throat, coughing, and even coughing up yellow phlegm. Patients with such symptoms can eat watermelon, as it can not only hydrate the body but also cool it down and provide some essential nutrients, making it suitable for patients with a heat-natured cold.