Heat wave turns deadly in United States

People pose next to a thermometer reading 131 degrees Fahrenheit (55 C) in Death Valley, California, which has been the site of a number of heat-related deaths over the years. Two German motorcyclists were overcome by the heat while traveling through the region as part of a group earlier in the week, with one taken to the hospital and the other pronounced dead at the scene.

Spanning the state line between Nevada and California, Death Valley is frequently the hottest spot on the planet. At 86 meters (284 feet) below sea level, it is also the deepest and driest land in North America, with the heat held in the valley by the surrounding mountains.

"Once heat index of 99F (37.2C) is exceeded, ambient air no longer helps provide relief," the US National Park Service warns on its website. "Heat illness and injury are cumulative and can build over the course of a day or days." Temperatures are projected to remain in the high 40s and low 50s Celsius for at least the next week.

Despite the warnings, many tourists leave their air-conditioned rental cars behind for a hike in the valley.

Just east of Death Valley, the heat wave has also affected life in the city of Las Vegas, Nevada, reaching a record 48.9 degrees Celsius on Sunday. And media in the Pacific Northwestern state of Oregon have reported at least four heat-related deaths.

The high temperatures are also increasing the threat of wildfires in California. Nearly 11,000 hectares (26,500 acres) of land have burned in the vicinity of Santa Clarita alone. Summer winds and abundant vegetation from the winter rains are feeding the flames.

From Florida to Maine, the East Coast of the United States is also suffering under the heat wave, the second of the summer for many states. The weather has sent New Yorkers streaming to parks, pools and beaches, such as the people's playgound, Coney Island.