U.S. likely claims hottest place on Earth as heat tightens grip on more than 100 million

On Tuesday, Death Valley, California, climbed to 124 degrees, making it not only the hottest spot in the United States but also likely one of the hottest, if not the hottest, locations in the world.

Wednesday was forecast to only get hotter, with Death Valley predicted to soar to a blistering 128 degrees.

With temperatures rising to 10 to 30 degrees above average, dozens of records were demolished Tuesday across Wyoming, Utah, South Dakota, Nevada, Arizona and Southern California. Casper, Wyoming, broke its previous record high of 93 by a full 9 degrees. Many other Western cities saw similar, even more extreme events: Billings, Montana, shattered its daily record by 10 degrees (new record: 108), and Chula Vista, California, smashed its record by a whopping 13 whole degrees (new record: 89).

All-time record temperatures were tied on Tuesday in Billings at 108 degrees, Salt Lake City at 107 and Cheyenne, Wyoming, at 94. New records for the hottest temperatures for the month of June were set in other portions of Utah, where temperatures soared above 105.

On Wednesday, the widespread extreme heat continued to engulf nearly 40 million people who found themselves under heat advisories, watches and warnings.

With the heat wave not expected to diminish until next week, more than 200 warm records could fall, including afternoon record highs and overnight lows that fail to cool down.

By the time it's all said and done, 110 million Americans will have faced highs above 90 degrees and over 20 million over 100 degrees.

Concerns grow as the high heat, low humidity and gusty winds overlap to produce ideal wildfire conditions.

Massive amounts of evaporation from key reservoirs, lakes and rivers caused by the unrelenting heat has resulted in dwindling water and energy supplies, spurring power grid operators in several states to implore residents to reduce their consumption.

Meteorologists urge everyone under the heat alerts to stay indoors, seek shade, drink water and check on neighbors who may need relief from the dangerous heat.

Extreme heat has one of the strongest correlations to the warming temperatures due to climate change. Heat waves are lasting longer and becoming more intense, and wildfire seasons across the West are seeing an increase in acres burned.

Kathryn Prociv is a meteorologist and producer for NBC News. 

Jeremy Lewan is an intern with the NBC News Climate Unit.