The Public Health Emergency Response Guide for State, Local, and Tribal Public Health Directors, developed by the National Center for Environmental Health (NCEH), Division of Emergency and Environmental Health Services (EEHS), Environmental Public Health Readiness Branch (EPHRB), is an all-hazards reference tool for health professionals who are responsible for initiating the public health response during the first 24 hours (i.e., the acute phase) of an emergency or Disaster. It provides useful information on the activation and integration of a jurisdiction's public health system into the existing overall emergency response structure during the acute phase of an incident. It also contains guidance that may be unique to specific types of incidents, such as floods, earthquakes, and acts of terrorism.