Chapter 3 discusses two common protective actions: sheltering in-place and evacuation. Sheltering in-place can provide shielding from the hazard and can be appropriate for hazards in which there is insufficient time to evacuate safely, such as tornados and some chemical accidents. Evacuation, on the other hand, reduces the time a person is exposed to a hazard and increases the distance from the hazard source. Both of these protective actions require time to implement. This chapter also discusses protective action selection and timing, uncertainty, and considerations for facilities with highly vulnerable populations.