Vomiting, nausea, and fever are often linked because many conditions that affect the stomach or the whole body can trigger all three symptoms simultaneously. Common causes include viral or bacterial stomach infections, food poisoning, the flu, dehydration, migraines, severe acidity, or reactions to certain medicines. The fever occurs as the body fights infection, while nausea and vomiting occur when the stomach lining becomes irritated. These symptoms can range from mild to severe, so if vomiting is persistent, the fever is high, you feel very weak or dehydrated, or symptoms last more than a day or two, it is essential to consult a doctor for proper evaluation and treatment.