Large congenital nevi form in the womb very early in development, within the first twelve weeks of pregnancy. They are caused by a defect during embryologic development. There is no known method of prevention. They appear in either sex, in all races, and on any areas of the skin.
I recommend that you have a carbon monoxide detector within 15 feet of each bedroom door, 10 feet is even better if you can afford more detectors. If two bedroom doors are 30 feet apart or less, then place one in the middle. If however they are more than 30 feet apart you will need more than one detector.
1 Contact a licensed electrician to install hard-wired smoke alarms that are wired into your household electrical system and that can be interconnected so that every alarm sounds regardless of the fire's location. 2  Install Carbon Monoxide (C0) detectors near any major gas appliances.ttaching or covering these devices could keep them from working in the event of an emergency. To have a local professional electrician install your smoke alarms and carbon monoxide detectors in Chicagoland then please call (773) 297-7177.