Is it normal for a baby to sleep a lot when having a cold?
Generally speaking, whether it is normal for a baby to sleep more when having a cold needs to be determined according to the baby's sleeping condition. If the baby sleeps more due to discomfort caused by the cold, it is usually considered normal. However, if there are other underlying medical causes, it is not normal. Detailed analysis is as follows:

When a baby catches a cold, the body must fight against the virus, which may make the baby feel tired and sleepy. This increased sleepiness is a natural response of the body while fighting the virus and helps the body recover its strength. Additionally, during the cold, the baby may take some cold medicine, which might contain ingredients that suppress the nervous system, causing drowsiness. If the drowsiness is mainly due to medication side effects and the baby has no other discomfort symptoms, this kind of sleepiness is usually normal, and parents needn't worry excessively.
A fever may accompany a baby's cold. Fever increases the body's energy consumption, causing fatigue and sleepiness. However, if the fever persists or the body temperature becomes excessively high, it may lead to severe symptoms such as listlessness and excessive sleepiness in the baby, in which case timely medical attention is necessary. In rare cases, a cold may trigger brain-related illnesses, such as encephalitis. These illnesses may cause symptoms in the baby such as excessive sleepiness, poor mental condition, nausea, and vomiting. If the baby develops these symptoms during the cold, especially if the symptoms last a long time or gradually worsen, parents should seek immediate medical attention for the baby.
During a baby's cold, parents should ensure the baby gets sufficient rest and sleep, while maintaining good indoor air circulation and an appropriate room temperature. Additionally, parents should give the baby plenty of water to replenish fluids and electrolytes needed by the body.