Searing Heat Wave Engulfs Millions Across American South

A sweltering heat wave is sweeping through the American Southwest and South. It's bringing triple-digit temperatures and heat indexes surpassing 120 degrees Fahrenheit.

A “heat dome” is the cause. This happens when areas of high pressure combine with sinking air. This traps heat near the Earth’s surface. A heat dome is like placing a lid over the top of a pot of boiling water. This seals in the heat beneath the dome.  

More than 55 million Americans are under heat alerts, from Arizona to Florida, according to CNN. Heat indexes in some cities are getting near dangerous levels of 120 degrees. The heat index measures how the temperature and humidity levels affect the human body.  

Making the daytime heat even worse is the nighttime. Many areas won’t cool down below the 80s at night, the National Weather Service warned. And there doesn't seem to be an end in sight. Forecasters have said the heat wave could go through the July 4 holiday.  

The heat has already killed several people. A teenager and his stepfather died while on a hiking trip in Texas’ Big Bend National Park over the weekend. The 14-year-old lost consciousness and his brother tried to carry him to safety. His stepfather ran to his vehicle to try and find help.

The stepfather’s vehicle crashed and he was killed. The teen died before park rangers could get to him. Another hiker also died in Big Bend of heat-related causes, a ranger told The New York Times.   

Reflect: How can extreme heat impact people’s daily lives and what steps can people take to stay safe during a heat wave?