Fire is not a Chinese medicine term, which generally refers to heat evidence. When longan is eaten in excess, it may cause heat evidence. Longan meat is sweet, warm and belongs to the heart and spleen meridians. Usually, eating longan in moderation will not cause heat syndrome or other effects on the health of the organism, but when a large amount of longan is eaten, it may induce heat syndrome due to the hyperactivity of yang qi in the internal organs or hyperactivity of yin (deficiency of yin fluid and hyperactivity of yang qi), which manifests itself as aversion to heat and preference for cold, thirst and desire to drink, irritability and restlessness, dryness of stools, red tongue, less fluid, and so on, which affects the quality of life. As longan meat has the effects of tonifying the heart and spleen (tonifying the heart and spleen with tonic drugs), nourishing the blood and tranquilizing the mind (stabilizing the mind and soothing the emotions by nourishing the blood), etc., it is commonly used clinically in the treatment of deficiency of qi and blood, palpitations (rapid heartbeat, often accompanied by panic), palpitation (rapid heartbeat and panic), daze (violent heartbeat and panic), forgetfulness and insomnia, and deficiency of blood wither and yellowish color. It is worth noting that people with internal dampness (too much dampness leading to fullness and discomfort in the spleen and stomach) or those with water retention (water stays in the body) or phlegm fire are forbidden to consume longan to prevent aggravation of the condition. Its adverse effects are not known. It is recommended to consume longan in moderation on a daily basis to replenish the nutrients needed by the body, and to follow the doctor’s instructions for diagnosis and treatment if necessary, and not to indiscriminately use Chinese herbs or prescriptions on one’s own.