Whenever there is a nuclear disaster firestorms inevitably result within an area of five miles of the original blast. Many of these fires would be caused by the blast of radiation from the fireball. There would be other effects from the blast that could cause fires as well. Furnaces and stoves would explode. Anything combustible would become part of the blast within seconds.
One way to protect fire from spreading in your home might be to whitewash the insides of window panes and around door frames. This can help prevent heat radiation from entering the home and setting drapes and other flammable materials. Sometimes heat radiation will simply charr a building and not burn it if it is whitewashed with a thick coating of slaked lime. If kept damp smearing a home’s walls with mud might also prevent it from burning down.
If you are inside a home made expedient shelter then you might want to keep extra cloths and plastic canopies on hand. These are easily blown away by hot blasting winds and may need to be replaced.
One real threat to survivors is forest and brush fires. More than being burned carbon monoxide and toxic smoke are a real threat. If large scale fires are burning near your shelter you could be in trouble. Carbon monoxide inhalation can cause death if only eight parts are in the air. It can cause headache, dizziness and nausea within 45 minutes and fatality within two hours.
Aside from carbon monoxide there can also be many other types of poisons in the air from industrial processes that could also kill when inhaled.
The problem is likely to be the smoke coming off burned rubble. In a zone of total destruction many residential and industrial buildings will be totally destroyed.
Whether you are in a basement shelter or in an expedient shelter you are well advised to stay in the shelter if you know there is a fire outside. Taking just a few simple breaths of toxin-infused air from outside can kill you if there are fires raging in the rubble outside.
It is also worth it to carefully consider where your intake vents are in the basement. Many hard core survivalists recommend an expedient hole-in-the-ground style shelter simply because shelters in basements are attached to houses that are full of combustible, toxic materials. When they burn the smoke is simply vented downstairs into your shelter where it kills you and your family.