Even if “Cold War” became a sapient part of history nearly twenty years ago and small conflicts are mostly taking place in the Middle East the world is still full of nuclear weapon. Thus it's important to have your preparations made even for such improbable but still nearly worst case scenario.

There are three types of nuclear explosion's damage. Each one of them is extremely dangerous and capable of causing lethal outcome.

• Blast (40-50% of total energy)
• Thermal radiation (30-50% of total energy)
• Ionizing and residual radiation (10-15% of total energy)

So there are also three ways you can notice an explosion and experience nuclear damage:

• Get hit by a blast wave – the most powerful and destructive of all nuclear effects
• See an explosion as a bright flash of light which is a sign of thermal radiation causing serious injuries and even death.
• Fallout radiation follows up afterwards as cause of over serious consequences.

Right after explosion.

The most important thing to do right after an explosion is to take cover as good as possible protecting you from nuclear heat and blats which can be inside of a building, vehicle, cellar, or any relatively stable and inflammable object. There are two things you should keep in mind:

• Nuclear heat generally appears few seconds before the explosion. So if you feel it or see it as a flash of light you might still have up to 25 seconds to get away from the blast.
• Taking cover from the blast wave consider a possibility of collapse. Meaning that hiding yourself in a cellar or somewhere underground would be certainly more reasonable rather choosing any other location inside the building.

After heat and blast passed.

First thing to do is to go to the closest and the most reliable fallout shelter as fast as you possibly can. Meaning that first hours after explosion are the most dangerous ones. In two hours radiation level drops up to 50%, in 4 hours it's roughly 5 times less, in 36 hours radiation level will drop 70 times approximately. Nuclear fallout can be dangerous during several days from an explosion. So in ideal you need to be prepared to have a safe location from it for up to two weeks. You can use the closest fallout shelter you can find which can be temporarily developed in a school, hospital or other public place. Or you can always built you own one in advance.

In case you're not aware of whereabouts of a nuclear shelter and you don't have one of your own in order to get maximum protection:

• Nuclear radiation seeps through any material however it constantly reduces while doing so. Thus getting inside will notably increase your chances of survival.
• Eliminate all openings by shutting all doors and windows.
• Get away from walls as much as you can.
• Try to support surrounding border with any materials available. Which can be bricks, wood, sand etc. You can even use furniture from another room for the same purpose.

Something to keep in mind building a fallout room:

• First of all, it needs to be an insulated structure. Meaning that making it an underground facility is a much better option rather have it as a bungalow, cabin or trailer. In fact such choice won't be a good idea at all.
• Try to make walls as massive and reliable as possible. For instance, using concrete will certainly be a good fit.
• Sometimes even a custom build fallout shelter won't be enough for a full protection during the first few hours after detonation. So you may want to build some kind of inner casket for an additional protection purposely for that critical period.
• Make sure you have enough lighting. There is a possibility of losing power so for such case you have to have candles as well as enough batteries if using electrical sources.
• In order to keep communication tight with an outside world make sure you have an FM/AM radio with extra batteries and separate emergency phone line if possible.
• You have to have enough supplies to be able to stay in your facility for at least two weeks. Minimum requirement is 1 gallon of water and 2500 calories meal per day for a person. An ideal scenario will be to have an additional gallon per day/person for cooking and washing. Obviously, you have to plan an advance where will you toilet. For most people even a minimum requirement could be difficult to achieve. Therefore, it's totally up to your imagination to make a survival room as relatively comfortable as possible for you and your family to use.