Final answer:
The time of day and recent food intake are crucial information to document after measuring a child's oral temperature, as they can influence the reading and its interpretation for health assessment.
Step-by-step explanation:
After a nurse measures a child's oral temperature, the most important information to document would be the time of day the temperature was taken. This is significant because body temperature can vary throughout the day and it's important to know when the reading was taken to properly assess the child's health status.
Other pertinent details include any recent food intake, as eating and drinking can affect oral temperature readings. While the ambient room temperature and the child's weight are important in the overall assessment of the child's health, they are generally less critical in the immediate interpretation of an oral temperature reading.