My infant son vomited while he was asleep. Does not have a fever. What should I do?

Monitor the situatio. Infant will often have the equivalent of a wet burp in light sleep stages. This can reflect their tendency toward gastoesophageal reflux after a good feeding & is not necessarily a sign of illness. Willingness to stay on a the regular feeding schedule & lack of other worrisome signs gives you time to monitor the situation & see if this progresses to something more involved.