A blistering heat wave blanketing California and other western states this week is breaking temperature records and elevating drought and wildfire risk. Residents should brace for conditions to get even worse.

On Thursday, more than 30 million Americans were living in places where temperatures soared above 100 degrees, meteorologists found, and 40 million Americans are currently under heat advisories or excessive heat warnings, the National Weather Service reported.

Daily and monthly temperature records have fallen across the entire western and southwestern U.S., which is grappling with dangerously high temperatures in California , Colorado , Utah , Arizona , Texas , Nevada and beyond. Many jurisdictions have called on residents to ration their power usage in order to prevent strain on electrical grids.