WASHINGTON (NEWSnet/AP) — A new color-coded heat warning system relies on magenta to alert US. residents to the most dangerous conditions.

National Weather Service and U.S. Centers for Disease Control and Prevention presented a new online heat risk system that combines meteorological and medical risk factors.

It involves a seven-day forecast, simplified and color-coded.

“For the first time, we’ll be able to know how hot is too hot for health and not just for today but for coming weeks,” said Dr. Ari Bernstein, director of National Center for Environmental Health.

Magenta is the deadliest of five heat-threat categories, hitting everybody with what the agencies call “rare and/or long-duration extreme heat, with little to no overnight relief.”

It’s a step higher than red, considered a major risk, affecting anyone without adequate cooling and hydration.

Red is used if a day falls within the top 5% hottest in a specific location. 

Other levels are pale green (little to no risk); yellow(minor risk, mostly to the young, elderly, sick and pregnant); and orange (moderate risk, affecting people who are sensitive to heat and without adequate cooling).

The five categories are based on strict science-set numerical thresholds, said Ken Graham, director at National Weather Service. It was calculated using local weather data, local climatology and localized medical data for heat illnesses.

Follow NEWSnet on Facebook and X platform to get our headlines in your social feeds.

Copyright 2024 NEWSnet and The Associated Press. All rights reserved.