The following reasons can be considered in terms of environmental factors: (1) The room temperature is too high: The room temperature should preferably not exceed 24℃, otherwise the child will easily become sweaty, uncomfortable, irritable and crying. (2) Irritants in the air: Irritants in the bedroom may block the baby’s respiratory tract and thus make crying occur. Irritants can be the smell of cigarettes, prickly heat powder, mosquito repellent flower lotion, paint, etc. (3) sound: when the child is in a light sleep stage, or in the process of going from deep sleep to light sleep, any sudden, loud, unfamiliar sound, can wake the child, causing a lot of crying.