What's A "Heat Dome"? A heat dome is caused by a combination of several factors that lead to extreme and persistent heat over a location. The National Ocean Service summarizes that they occur "when the atmosphere traps hot ocean air like a lid or cap."

Big Picture: Texas has recently been impacted by high temperatures caused by a heat dome. While this heat continues to remain over Texas, Oravec says the hot weather will spread "north to Kansas City and the entire state of Oklahoma, into the Mississippi Valley ... to the far western Florida Panhandle and parts of western Alabama." In Texas, the state's power grid operator has asked residents to voluntarily reduce usage due to an expected demand on the system, and on Tuesday, AccuWeather reported that "More than 46 million people are under heat alerts as a dome of heat spreads across the South Central U.S."

Why It Matters: Extreme heat poses health risks, especially to vulnerable populations including children and the elderly. However, "Even young and healthy people can get sick from the heat if they participate in strenuous physical activities during hot weather," the Centers for Disease Control and Prevention notes. The CDC's Heat & Health Trackers reports that each year, there are 702 heat-related deaths and more than 67,000 emergency department visits related to heat, on average. During hot weather, protective actions include limiting outdoor activity, drinking more water than usual ("even if you don't feel thirsty"), and checking on friends or neighbors (CDC).

What is a heat dome? Scorching temperatures in Texas are expected to spread to the north and east (The Associated Press)

Deadly heat roasts Texas as temperatures top triple digits (AccuWeather)

Keep Your Cool in Hot Weather! (CDC's National Center for Environmental Health)