Washington, Jul 15 (IANS): More than 113 million people in the US are currently under heat wave advisories, with warnings issued across the southwest up to Washington state.

In its latest update, the National Weather Service (NWS) said that around 27 million people are forecast to experience temperatures over 43 degrees Celsius in the coming days, reports the BBC.

The heat wave advisories on Friday night were issued from Florida to Texas to California.

Saturday will also be exceptionally hot, with daytime highs forecast to hit up to 46 degrees in some areas, the NWS said, adding that the scorching heat is expected to linger until next week.

The Weather Service said the excruciating heat was a result of an upper level ridge of high pressure, which typically brings with it warmer temperatures.

The agency added it is "one of the strongest" systems of its kind that the region has ever seen.

"The subtropical ridge responsible for this likely historic heatwave across the region is not showing signs of letting up anytime soon," the BBC quoted the NWS as saying.

Phoenix, the state capital of Arizona, is on course to break its longest hot spell record with the forecast for the next five days expected to hit or exceed 43 degrees.

The all-time record is 18 days and the city has already seen 15 days of 43 degrees temperatures.

The NWS further saud Las Vegas may match its all-time high of 47 degreesin the next few days, while Death Valley, California -- one of the hottest places on Earth -- could surpass its official all-time high temperature of 54 degrees.

The NWS in Las Vegas warned locals, who might think they can handle the temperatures, that this is "not your typical desert heat".

"'It's the desert, of course its hot'- This is a DANGEROUS mind set! This heatwave is NOT typical desert heat due to its long duration, extreme daytime temperatures, & warm nights. Everyone needs to take this heat seriously, including those who live in the desert," the agency said in its tweet

Parts of the southwestern US have already grappled with intensely hot temperatures over the past week.

While parks, museums, zoos and businesses have either announced closures or shortened hours because of the extreme heat, hospitals were also seeing heat-related admissions.

Overnight temperatures were expected to remain "abnormally warm" in some areas, offering little night-time relief from the heat, the BBC quoted the NWS as saying in its update.

Demand for power in Texas has surpassed record numbers for two days in a row because of the heat.

The Electric Reliability Council of Texas (ECROT), which manages 90 per cent of the power load in the state, said its usage hit a preliminary 81,406 megawatts on Thursday, topping Wednesday's record of 81,351 megawatts.

ERCOT said it expects power usage on Friday to surpass those numbers, though the agency said it had enough resources to meet the demand.