You may also be given instructions in an emergency that involves HAZMAT, or chemical, biological, or radiological contaminants that are released into the environment, accidentally or intentionally, to seek shelter-in-place to keep you safe and indoors.

When officials instruct the public to seek shelter-in-place, they want it to be immediate, which means wherever you are, whether the event occurs when you are at home or at work, you should not leave or drive or go outside.

During a shelter-in-place event, you must select and take refuge in a small interior room that is above ground level with no, or few, windows. Some chemicals may seep and pool into basements even if the windows are closed, because they are heavier than air, which is why you want to choose an upper-story room during any sort of HAZMAT threat.

Plan a room that has your home's land telephone line because cell phones may be damaged or the lines overwhelmed during an emergency. Remember, shelter-in-place does not require you to seal off your entire home or building, only the room where you have taken refuge.

To create a shelter-in-place at home, perform the following steps:

• Close and lock all windows and doors to the exterior.

• Turn off fans, heating, and air-conditioning systems.

• Close your fireplace dampers.

• When there is also danger of explosion, close curtains, window shades, and blinds.

• Take your family disaster-supplies kit along with your radio, your pets, and their food and water supplies.

• Using heavy plastic sheeting and duct tape, seal all cracks around any vents, windows, and the door.

• Keep your radio or television on and stay inside until you are told by officials that it is safe or you are instructed to evacuate.

If you are at work, participate in closing the business and ask any clients, customers, or visitors in the building to stay in order to provide them with safety. Then do the following:

• If it is safe to do, everyone in the building should make contact with their persons to contact in case of emergency, letting them know where they are and that they are safe.

• Put all phones on call forward, telephone-answering systems, or other available services.

• Record a voice mail saying that the business is closed and that all employees and other persons plan to remain inside the building until they are instructed by authorities that it is safe to leave.

• Close and lock all exterior doors, windows, and other exterior openings.

Essential

Wherever you may be during a HAZMAT event, remember that shelter-in-place instructions are usually instituted for only a few hours, not days or weeks, so don't be alarmed about oxygen, food, and water running out.

• For any danger of explosions, close curtains, window shades, and blinds just as you would in your home shelter-in-place.

• Fans and heating and air-conditioning systems should be turned off, sealed, or disabled by employees that understand the building's systems, particularly those systems that automatically vent and exchange inside air with outside air.

• Everyone then needs to gather in the safe room, and shut and lock the doors.

• Record the name of everyone in the room. Then call the designated emergency contact for your business to report the number of people in the room, their names, and whether they are an employee, customer, visitor, or client.

If you are at school, the school needs to close and the school's emergency plan needs to be activated immediately, and all students, faculty, visitors, and staff need to come inside. Follow all previously stated shelter-in-place procedures. In addition, the following steps should be taken:

• At least one land-line telephone that shows the school's listed number when calling from the school should be in the rooms used for shelter-in-place.

• The school secretary or some other designated person needs to answer telephone inquiries from concerned parents.

• There needs to be a provision for communication between all rooms where people are sheltering-in-place.

• Students should be allowed to use their cell phones to contact parents and guardians.

• Ideally, announcements should be made over the school-wide public-address system.

• Change the school voice-mail message to indicate that the school is closed and the students and staff are staying inside until advised that it is safe to leave by authorities.

Use several rooms such as classrooms, any large storage or utility rooms, meeting rooms, and even gymnasiums that don't have exterior windows so that there will be no problems associated with overcrowding.

If you are in your vehicle and hear a shelter-in-place announcement:

• If you are very close to home, work, or a public building, drive there immediately and go inside.

• If you are unable to get to any building promptly and safely, pull over to the side of the road and park in the shade or under a bridge to keep the car's interior from becoming overheated.

• Turn off the engine and close the windows and all vents.

How can I find out what disasters can happen in my community?

Be prepared ahead of time for any potential disasters. You can find all the information you need for disaster preparedness at Ready.gov.

• If you are carrying duct tape in your emergency kit, use it to seal the heating and air-conditioning vents.

Stay updated by listening to the radio regularly, and do not leave until informed that it is safe. Follow all directions of law-enforcement officers about traffic that may be detoured and roads that may be closed, and the instructions of local officials regarding shelter, food, water, and clean-up methods during and after any disaster or emergency. It is their role to help you stay safe.