Ever since the 1950’s it's been all the rage to have your very own nuclear fallout shelter. Sadly, your parents or landlord didn’t build one, and most likely wouldn’t let you build a huge 500 ft underground bunker just for kicks. That’s right: most likely, should there be a large scale nuclear war, you wouldn’t survive. Since most of the worlds nuclear weapons are in the hands of sane leaders, a nuclear war probably won’t be affecting you anytime soon.
What just might possibly happen sometime in the future is a terrorist getting his/her/its hands on a nuclear weapon and detonate it in a city. No warning, which means no time to get to your underground bunker and live out your life eating ramen noodles. This is a guide should you find yourself in a situation in which some evil terrorists bring a briefcase nuke to your fair city.
What to do when you see the light
A nuclear blast is about four times as bright as the sun. You’ll know when it goes off. The 1st and foremost thing to do when you’ve realized a nuke has gone off; do NOT look at the blast. If you do, you’ll go temporarily blind, and groping the floor is not a good way to find shelter before the blast wave hits. You’ll also get those little spots you see when you poke your eye or look at the sun permanently burned onto your eyes and you will have them for the rest of your life. So just DON’T look at the light, it’s a very bad idea.
Heat (35% of a nuke’s energy)
The thermal pulse of a nuclear bomb is the real wammo. If you’re out in the open when it hits, you’re dead. It’s deadly to about four miles away; from there on its just burns and flying glass from the shock wave. If you’re uncovered and less than 4 miles from ground zero when the thermal pulse hits you’ll get severe burns and your clothes will most likely catch on fire. The good news is that fog or buildings between you and ground zero severely reduces the thermal blast wave’s energy. Dive behind anything that has a shadow. Really quick like. This is very important.
Blast Wave (50%)
After you’ve seen the bright light and felt the flesh-burning heat, run for cover. You only have few seconds, depending on how close you are to ground zero. Get inside or under something that won’t move when the blast wave hits, like a large car (SUV preferred). Even better is inside a brick or concrete building which didn’t catch on fire when the thermal pulse came. You will likely be near several Starbucks cafés which are almost always made of brick. Take cover in the back closet, away from windows. When you’re covered by your cover, wait. When the blast wave hits, there will be tons of pressure outside, shattering windows and hurling glass, wood, small mammals around. Depending on how far you are from the blast, winds will range from 30 mph to about 600mph. These only last a few seconds, but you still wouldn’t want to be caught in 600mph winds, because they will most certainly rip you to pieces. If after two minutes nothing happens, congratulations, the light you saw was not a nuclear explosion, or the nuclear explosion just happened far away from you, and the blast wave hasn’t made it to your location. Lucky you.
Initial Radiation (5%)
The initial radiation will be released during the 1st minute following the blast. It's not deadly unless you are about a mile from the blast, and if you’re that close the blast wave and searing heat have already killed you, unless big buildings have blocked it. You’ll know whether the radiation is fatal after about the 1st 5 minutes. The EMP from the blast will have knocked out all unshielded electronics, so you won’t be able to escape the area in a car or a plane. Your cell phone will be fried, along with your PDA, pager, and Furby.
Fallout (10%)
Fallout will affect tons of people, all across the country. When Mt Saint Helens blew up, ash fell all over the country. A nuclear bomb’s fallout is like that, except the ash is radioactive and if you get covered in it, odds are you’ll get cancer very soon. The nuclear ash will be sucked into the middle of the troposphere along with the flames in the trademark mushroom cloud. Heavy pieces of radioactive ash will rain down as far as 15 miles from ground zero. The light pieces, which are still dangerously radioactive mind you, will be carried downwind for hundreds of miles. This will almost certainly affect you, but be grateful you weren’t in the blast radius. Since you don’t have your very own ramen noodle shelter, you will be exposed to the radioactive fallout. The best way to keep your body safe is to take iodine tablets. These will fill your thyroids with stable iodine, so that when radioactive iodine gets into your system, your body will be forced to expel it, as your thyroids are already filled up. This is the easiest way to live with radioactive fallout, but it's also a good idea to close your windows and wash your clothes a lot to keep you away from radioactivity, because even if your thyroid is safe, the rest of your organs are not.
Doses and effects:
Bone Marrow Syndrome (>100 rad): damage to most rabidly dividing cells, like your blood, spleen, and lymphatic tissue. Symptoms include internal bleeding, fatigue, bacterial infections, and fever.
Gastrointestinal tract syndrome (>1000 rad): Damage to your gastrointestinal tract. Symptoms include nausea, vomiting, diarrhea, dehydration, electrolytic imbalance, loss of digestion ability, bleeding ulcers, and the symptoms of bone marrow syndrome.
Central nervous system syndrome (>5000 rad): Damage to non-dividing cells, like brain cells. Symptoms include loss of coordination, confusion, coma, convulsions, shock, loss of interest in E2, and the symptoms of the bone marrow and gastrointestinal tract syndromes.
About 600 rad to your genitals will permanently sterilize you. Anything above 600 rad to your entire body will result in your death within two weeks.
Sources: Fema website (fema.gov) and the Nuclear Blast FAQ