You can turn on the air conditioner after the MMR vaccination, but you should be careful not to set the temperature too low, and pay attention to keep warm so as not to get cold. The MMR vaccine is a triple vaccine, which is a live attenuated vaccine that introduces a weaker virus into the body, which may lower the body’s resistance and thus may increase the adverse reaction of the vaccine or increase the risk of infection. If the room temperature is set too low at this time, it may cause the body to get cold, which may lead to colds in the patient, so it is important not to set the temperature too low. In addition, patients should eat a light diet and avoid spicy and irritating foods, such as chili peppers, ginger and garlic, to avoid skin discomfort. Within 24 hours after vaccination, patients should not take a shower or get their skin wet to avoid skin infections. It is recommended that patients need to open the air conditioning after the MMR vaccine, do not set the temperature too low, and pay attention to warmth, according to the weather changes in time to add clothing, so as to avoid discomfort caused by cold.