What should I do if my seven-month-old baby has a fever? A fever in a seven-month-old baby is a problem that parents often encounter. Babies are weak and have low immunity and are susceptible to diseases. Fever is a way for the body to send out an alarm. When dealing with baby fever, parents need to pay attention to the following aspects: 1. Methods to deal with baby fever 1.1 Measuring body temperature: Measuring the baby\’s body temperature is the first step to detect the baby\’s fever. It usually requires the use of an electronic thermometer or a mercury thermometer.