Some kids have difficulty falling asleep when the room is too warm. Keeping the body cool slows down all of the metabolic processes. Try lowering the temperature of the room if your child has insomnia.
The blue light glow from a TV, computer, cell phone, or digital clock may be keeping your child awake. The blue light suppresses the secretion of melatonin (a sleep promoting hormone). If your child has insomnia, have them read a book rather than watch TV or use the computer before bed. Also try covering up digital clocks if their light is blue colored. You may also want to replace the bedtime reading light with an orange light bulb. It’s glow lets you read or relax without actively inhibiting melatonin.