LOS ANGELES — A relentless and unprecedented heat wave continued its sweep across the United States, scorching parts of the West and tightening its grip on the East Coast with oppressive temperatures, resulting tragically in the death of a motorcyclist in Death Valley.

As of Sunday, an excessive heat warning—the National Weather Service’s most severe alert—remained in effect for approximately 36 million people, constituting about 10% of the nation’s population, according to meteorologist Bryan Jackson. Numerous locations throughout the West and Pacific Northwest either matched or shattered previous heat records.

Northern California endured particularly extreme conditions, with temperatures soaring beyond 110 degrees Fahrenheit. Redding, in a remarkable turn of events, soared to a record-breaking 119 degrees Fahrenheit. Meanwhile, Phoenix set a new daily record for its warmest low temperature, maintaining a minimum of 92 degrees Fahrenheit throughout the night.

Tragically, the relentless heat claimed a life in Death Valley National Park, where temperatures surged to an unprecedented 128 degrees Fahrenheit on both Saturday and Sunday. In the scorching heat, one visitor succumbed to heat exposure on Saturday, while another from the same group of motorcyclists required hospitalization for severe heat illness. Emergency medical helicopters were grounded due to the extreme temperatures, which exceeded safe operating limits for aircraft.

Despite the dangers, some visitors, like Chris Kinsel from Las Vegas, embraced the extreme conditions as a personal milestone. "Death Valley during the summer has always been a bucket list thing for me," Kinsel shared enthusiastically, noting the fulfillment of a long-held ambition to experience one of Earth's hottest places in July.

Across the border in Nevada, families sought respite from the blistering heat at water parks and higher elevations such as Mount Charleston, which hit a record-high temperature of 120 degrees Fahrenheit on Sunday. Natasha Ivory, accompanying her children, remarked, "They're having a great time. I'm going to get wet too. It's too hot to resist."

In Oregon, triple-digit temperatures persisted, with Salem setting a new record at 103 degrees Fahrenheit, surpassing the previous mark set over six decades ago. On the East Coast, although temperatures soared above 100 degrees in many areas, no excessive heat advisories were issued for Sunday.

Authorities issued stern warnings about the risks of heat-related illnesses and fatalities as the heat wave persisted. In Arizona's Maricopa County, which encompasses Phoenix, reports indicated at least 13 confirmed heat-related deaths this year, with over 160 additional deaths under investigation for potential heat-related causes. These tragic incidents underscored the severity of the ongoing heat wave and emphasized the critical need for public safety measures.

Furthermore, the scorching conditions exacerbated California's wildfire challenges, with firefighters battling multiple blazes amid low humidity and high temperatures. In Santa Barbara County, the Lake Fire had scorched over 25 square miles of dry vegetation by Sunday, prompting evacuation orders for some rural residences as containment efforts continued.

Looking forward, the forecast predicted even more extreme highs, potentially reaching 130 degrees Fahrenheit at Furnace Creek, Death Valley, later in the week. Although the hottest temperature ever recorded on Earth stands officially at 134 degrees in Death Valley in 1913, recent measurements suggest the record might be closer to 130 degrees, recorded in July 2021.

Reflecting on her decision to experience this extreme weather phenomenon firsthand, Tracy Housley from Manchester, England, said, "We just thought, let's be there for that," highlighting the allure of witnessing record-breaking heat despite its dangers.

As the heat wave persists across the West and grips the East Coast, communities remain vigilant against its formidable impacts, from health risks to heightened wildfire activity. This underscores the urgent need for resilience and precautionary measures in the face of relentless summer heat.