They produce large amounts of poisonous carbon monoxide. Lights Plan to provide some lights for your family to continue a somewhat normal existence. You won't be able have as much light as normal but you will have enough to operate for a few days. But if you need to summon emergency assistance it will be a problem. Normal emergency responders may be busy or you may not be able to contact them immediately.
Medical emergencies can happen at any time.
Have fire extinguishers available and learn how to use them. Contact your local fire department for classes or other instruction in their use. Make your home as fire safe and injury safe as you can. Medication Be sure you have a sufficient supply for at least 72 hours. If your pharmacy or their suppliers have computer problems it may take a while to get more.