“NOAA is expanding the availability of a new experimental heat tool called HeatRisk ahead of the hot summer months. A collaboration with NOAA’s National Weather Service (NWS) and the Centers for Disease Control and Prevention (CDC), HeatRisk provides information and guidance for those who are particularly vulnerable to heat and may need to take extra precautions for their health when the temperature rises. HeatRisk provides historical context for high temperature forecasts, identifying how unusual the heat will be for any given time of year across a spatial area with coverage across the contiguous U.S. It also identifies temperatures that are expected to bring increased heat impacts over a 24-hour period, up to seven days in advance.  The tool takes into account cumulative impacts of heat by identifying the expected duration of the heat, including both daytime and nighttime temperatures. HeatRisk is divided into a number and color-coded scale — ranging from zero to four and minor to extreme  — that identifies the risk of heat-related impacts…”