Baby sweating on the head when sleeping is because the head accounts for a larger body surface area of the whole body, and more hair, thus more pores, which is conducive to heat dissipation, so the head sweats more, while the body does not sweat. Sweating on the head is common in the following cases: 1, the indoor temperature is too high or the baby is wearing too thick, which leads to overheating, pay attention to the appropriate temperature of the indoor environment, wearing comfortable. 2, vitamin D deficiency rickets, mostly seen in 3-4 months of age, sweating at the same time accompanied by pillow baldness, night terrors, night crying and other symptoms, after giving vitamin D and calcium supplements, appropriate amount of outdoor activities, sunshine, will gradually be improved. It will gradually improve with vitamin D and calcium supplementation, moderate outdoor activities and sun exposure.