Why kids get more sick in the middle of the night:

During the day, sick children are sitting up, coughing to clear their lungs and throat, and drinking liquids regularly. At night, they lie prone, and don't often cough while asleep. The germs and mucus we associate with illness build up, forcing the body to fight harder-- often with a fever or other harsher symptoms. Drinking liquids washes out our system, supporting healthy cells and removing many germs and fluids. Also, kids have entertainment during the day to keep their mind off how icky they feel. The same isn't true in the dark at night.

Prop your child up with pillows, keep the bedroom warm, and provide a sippy cup or lidded waterbottle full of plain water or pedia-care. Encourage your child to take a few sips if they wake in the night. Also, a few favorite books within arm's reach, and a flashlight for fun might make the night easier for a sick child to bear.