Thanks for following along on the latest about the US heatwave, where parts of the country's southwest are expected to see record-breaking temperatures throughout the weekend.

We will be pausing our coverage, but will bring you more updates later as they become available.

This page was edited by Marianna Brady and Brandon Livesay with reporting by Nadine Yousif, Sam Cabral and Brandon Drenon.

Excessively hot temperatures can cause both heat exhaustion and heatstroke. The two are different, but the former is a precursor to the latter.

For signs of heat exhaustion, here is what you should look out for:

• Feeling faint or dizzy
• Excessive sweating
• Clammy skin
• Nausea or vomiting
• Muscle cramps

On the other hand, if you or someone near you are suffering from heatstroke, the symptoms are:

• Confusion
• No sweating
• Temperature over 40C (104F) with hot, dry skin
• Nausea or vomiting
• Losing consciousness, convulsions or seizures

You can read more about the symptoms, as well as what to do if someone near you is suffering from heat exhaustion, here.

The National Weather Service told Californian's to brace for "dangerously hot conditions" this weekend, with temperatures in some parts of the state expected to reach a sweltering 47C (117F).

It will "rival some of the worst heat waves this area has ever seen", according to officials from the California Governor's Office of Emergency Services .

The group met on Wednesday to discuss strategies over how the state will protect its residents from the extreme temperatures.

The state is home to the country's largest homeless population - more than 150,000. Unable to take refuge inside of air conditioned homes, they are some of the most at-risk.

Libraries and other public facilities will be converted into "cooling centres" for those without access to air conditioning, officials announced, which includes more than just the homeless.

As residents look to crank up the air conditioning and cool off, it causes a stress on the state's power grid which, in the past, has led to days of "rolling blackouts". That means no electricity and potentially no escape from the heat.

The national weather service says more than 113 million people in the US are now under various extreme heat advisories, watches and warnings.

It's the highest number since 28 June, when 120 million people were under heat alerts.

Brandon Drenon
Reporting from Washington DC

The extreme temperatures scorching much of the US this weekend are nothing new for Gary Martin.

Martin is a 30-plus year resident of Rio Grande Village, Texas, a place where, in June, the average temperature was 43.1C (109.6F) - and the high was 48C.

"This was more than hot," Martin said. "I mean you'd step outside and it's like sticking your head in a convection oven."

On that day, a teenage boy and his stepfather died while hiking in Big Bend National Park (Rio Grande Village sits inside the park, along the southern most point, at the US-Mexico border).

Martin's advice for those faced with these temperatures: "Stay indoors."

Image source, Getty Images

As we've mentioned earlier, large cities in the southwestern US, like Phoenix and Las Vegas, are under excessive heat warnings.

But just how significant is this heatwave compared to what these cities have seen before? Some of it has to do with how long the heat will last, as opposed to the temperature itself.

Here is a breakdown:

• In Phoenix, temperatures of at least 110F (43C) have been seen for the 13th consecutive day. If this trend continues like forecasters predict, the city will likely break its record of 18 days straight of extreme heat, set in June 1974.
• Las Vegas is projected to see a high of 117F (47C) on Sunday, which is the city's all-time high for hottest temperature on record, set on 24 July, 1942, and matched again in July of 2021.
• In El Paso, Texas, temperatures have been in the triple-digits Fahrenheit for 27 consecutive days, and the extreme heat is projected to continue. This breaks the city's record of 23 days set in 1994.
• Forecasters are watching whether Death Valley, California will break its (reliably-recorded) all-time high temperature of 130F (54C) set in August 2020 and seen again in July 2021.

Heatwaves don't often get the attention of other natural disasters - but that doesn't mean they are any less harmful.

The Centre for Disease Control estimates that around 700 Americans die each year from heat-related causes.

That is because constant exposure to heat can cause some serious damage to our bodies.

As the body gets hotter, blood vessels open up. This leads to lower blood pressure and makes the heart work harder to push the blood around the body.

This can cause mild symptoms such as an itchy heat rash or swollen feet as blood vessels become leaky. At the same time, our body is losing fluids more quickly because of the heat.

If the blood pressure drops too far, the risk of a heart attack as a result of the heat rises.

Read more about the impact of heatwaves, as well as how you can protect yourself, here.

Image source, Getty Images

Arizona is already known for its blistering temperatures in the summer - so how is this week any different?

The state has seen temperatures hovering around 100F (38C) for two weeks now, and it's expected to get even hotter this weekend.

Phoenix just recorded its 13th day in a row of temperatures above 110F (43C). If it reaches 18 days in a row over 110F, it will break a record set in 1974.

The city is helping locals cope with the heat in multiple ways. This includes cooling shelters for unhoused people and wellness calls made by volunteers to seniors and those living alone.

More than 10,000 aluminium water bottles and 100,000 plastic water bottles will also be given out to residents as part of a heat relief program.

Officials have been keen to get messaging out there to protect people from heat-related deaths, like asking people to stay vigilant and ensure that their pets or children are not left behind in locked cars.

They have also asked people to stock their cars with water and sun protection, as well as carry charged phones and plenty of gas when driving.

Image source, EPA

As the southwestern US bakes in record-breaking heat, Europe is also experiencing some of its hottest temperatures on record.

The heat is expected to hit above 104F (40C) in parts of Spain, France, Greece, Croatia and Turkey.

There are reports of several people, including tourists, collapsing in the heat in Italy. At least one person has died.

Read more of our coverage here.

Most areas in the southwestern US are under some sort of National Weather Service heat warning, whether it is Heat Advisory or an Excessive Heat Warning.

But what is the difference between the two?

• A Heat Advisory is typically issued within 12 hours of the onset of extremely dangerous heat conditions. Typically, this advisory is issued when the maximum heat is expected to be 100F (38C) or higher for at least two days, with night temperatures above 75F (24 C). Under this advisory, people are advised to take precautions to protect themselves from the heat, or else they may become seriously ill or die.
• An Excessive Heat Warning is more extreme than a Heat Advisory, and is issued when the temperature is expected to be 105F (41C) or higher for at least two days.
• The National Weather Service will sometimes issue Excessive Heat Watches, which warn of the possibility of an extreme heat event often 24 to 72 hours in advance. This is used when the timing of the heatwave remains uncertain.

The National Weather Service, external has issued extreme heat warnings for multiple states. Here is a break down of which areas will see the hottest temperatures on Thursday:

• Phoenix, Arizona - Forecast high: 115F (46C)
• Las Vegas, Nevada - Forecast high: 118F (47C)
• Houston, Texas - Forecast high: 100F (38C)
• Death Valley, California - Forecast high: 117F (47C)

Image source, Getty Images

Hello and thank you for joining our coverage on what is being called a “historic” US heatwave.

More than 100m people are under extreme heat advisories this Thursday, spanning across the southern US states, as the country grapples with what is projected to be record-high temperatures.

The heatwave is expected to worsen throughout the weekend. In some areas - like Death Valley, California and Phoenix, Arizona - temperatures are expected to hit a high of 122F (50C) over the next few days.

Stay tuned as we bring you analysis on this heat, as well as coverage on how cities and states are preparing for the weather.