Stomach pain with vomiting and low fever when there is a big change in weather may be caused by cold, heat stroke and acute gastroenteritis. 1. Cold: When the weather suddenly becomes colder, it is easy to cause the body and stomach to get cold, which affects the normal blood circulation and can cause stomach pain and vomiting. At the same time, a cold body can easily cause a low fever. 2. Heatstroke: When the weather becomes hotter, the body is prone to heatstroke, leading to water electrolyte disorders, which can cause gastrointestinal spasms, which can lead to stomach pain and vomiting. At the same time, due to the increase in body heat production, can cause a low fever. 3. Acute gastroenteritis: the weather suddenly becomes colder, the abdomen is stimulated by the cold, can lead to gastrointestinal digestion and absorption function is weakened, can increase the acute attack of gastroenteritis, can cause stomach pain, vomiting, low fever and other symptoms. When the weather changes, you need to do a good job of protecting yourself and adding or subtracting clothes in time. Meanwhile, if you have stomach pain with vomiting and low fever, you need to consult a doctor.