And though it may sound surprising, the best way to stay protected before, during, and after a nuclear detonation, is getting inside. Similar to protecting yourself from tornadoes or hurricanes, getting and staying inside a sturdy building would offer protection from the explosion's shock wave, heat, and radiation. The shock wave of energy would travel several kilometers beyond the fireball's radius in the first few seconds. Sturdy buildings within that range should be able to withstand the shock wave, and staying in the centers and basements of these buildings also helps provide protection from heat and flying objects. Finding shelter is especially important if the fireball occurs close to the earth, as it will pull thousands of tons of dirt and debris several kilometers into the atmosphere. As the fireball cools, unstable atoms created by the nuclear fission mix with the debris to produce the most dangerous long-term effect of a nuclear detonation: radioactive particles called fallout. These sand-sized particles emit-ionizing radiation, capable of separating electrons from molecules and atoms. Exposure to massive amounts of this radiation can result in cell damage, radiation burns, radiation sickness, cancer, and even death. Thankfully, the same buildings that offer protection from the blast are even better at guarding against fallout. Radiation is reduced as it travels through space and mass. So while a broken window and sealed window both have the same minimal effect on radiation, thick layers of steel, concrete, and packed earth can offer serious protection.