One must take note of various factors while keeping the infant or child in a room with air-conditioner or air-cooler.
Ensure that the cold air blowing out of the air-conditioner directly on the face/body of the infant/child. As this air is high in moisture content, the child will have difficulty in breathing. Even as the parent sleeps adjacent to the child, he/she may not notice the child having difficulty in breathing.
It must be made a regular routine to clean the filter in the air-conditioner at least once a week and remove all the dust collected. Otherwise, minute dust particles may enter the childs breathing system. In order to remove this dust, the lungs will have to produce extra phlegm. This might be the reason for the child catching a cold quite often.
The child cannot infer or tell the body temperature changes it experiences. So, please do not take the children from relatively very warm areas suddenly to the relatively cold air-conditioned enclosures. Further, please do not keep the temperatures at low levels (15 or 17 degrees) as soon as entering the room.
As warm air blows across during the night periods, the children will prefer to sleep without wearing any shirt with open breasts, Do not allow this. In case the child is a grown one (above 3 years of age), ensure that the chest is covered properly, If the child is younger, ensure to cover he chest as well as the feet/palms with clothes.
Sleeping with the head covered completely will result in insufficient oxygen for the breathing system. The same concept applies to the air-conditioner as well. By closing all the outlet doors in the room and sleeping, there will be insufficient oxygen in the room. Even though the air-conditioner has the provision to admit the air from outside into the enclosure, it would still be better to have a small opening. Only this would ensure that there is sufficient oxygen for the child. Otherwise, the child may be forced to breathe the air let out by your breathing.