The only way to transfer the Brass to the child is to beat him/her with it the temperatures involved is to low to even begin to affect the brass. I f you are worried of the smoke affecting your child set one room aside for hookah smoking install an extractor fan close the door and the fan should create enough negative pressure in the room to pull clean air from the rest of the home and vent the smoke laden air outside. Smoking with a window open can be chilly but the cold air from outside could push part of the smoke laden air back into the house thus actually negating that witch you wish to achieve.
The Tobacco and coals should be kept out of reach off children.
(Strange we lock tobacco medication Cigarettes and Alcohol away to prevent harm to our children But leave the bleach, Draino insecticides and pesticides easily accessible in a an unlocked cupboard under the sink) makes one wonder