Death Valley National Park has asked tourists not to test out the reputation of the world's hottest spot by frying eggs on the ground, citing a growing litter problem at the popular US landmark.

"An employee's posting of frying an egg in a pan in Death Valley was intended to demonstrate how hot it can get here, with the recommendation that if you do this, use a pan or tin foil and properly dispose of the contents," the park said on its Facebook page last week.

"However, the Death Valley NP maintenance crew has been busy cleaning up eggs cracked directly on the sidewalk, including egg cartons and shells strewn across the parking lot.

"This is your national park, please put trash in the garbage or recycle bins provided and don't crack eggs on the sidewalks," it said.

Death Valley, located in California and Nevada, will soon celebrate the 100th anniversary of its posting the world heat record -- 134 degrees Fahrenheit (57 degrees Celsius) -- on July 10, 1913.

The US Southwest has been in the grip of a massive heat wave in recent weeks, with temperatures at the park in the high 120s.

Japan heatwave kills 3, hospitalises 2,500
Tokyo (AFP) July 09, 2013 - Sweltering temperatures and scorching sunshine have killed three people and sent more than 2,500 to hospital across Japan in a week, the government said Tuesday.

The mercury hit 39.1 Celsius (102.4 Fahrenheit) in Yamanashi in the centre of the country on Tuesday, while dozens of other spots recorded temperatures of 35 Celsius or more.

A total of 2,594 people were hospitalised in the first week of July due to the effects of heat, with three of them dying, the fire and disaster management agency said in a report.

More than 42 percent of them were aged 65 or older, the agency said.

Incidents of children being hospitalised after outdoor school events were also recorded.

News reports feature frequent reminders to drink plenty of fluids and avoid prolonged periods outdoors, in what has become a regular feature of the sticky summer months.

The heat wave struck nationwide this week with high-pressure systems sitting over the Japanese archipelago, bringing an earlier than usual end to the rainy season.