We're going to start with the extreme weather that's being experienced across four continents, a sign that climate change may again help push temperatures beyond the record-breaking heat last summer.

In Saudi Arabia, there are reports that more than 1,000 people have died, pilgrims at the annual Hajj festival, killed by the stifling heat.

We'll have more on that in just a moment.

In India, there have been several deaths.

In the capital Delhi, temperatures were reaching more than 50 degrees Celsius.

In Europe, temperatures have also risen, with Greece experiencing its earliest-ever summer heatwave.

And in the United States, there are wildfires on one coast, made worse with high temperatures, and a tropical storm brewing on the other.

Well, scientists from the World Weather Attribution have released a report today saying that human-induced climate change made recent extreme heat in the US southwest, Mexico and Central America, around 35 times more likely.

In their new report, scientists said such a heatwave was now four times more likely than it was in the year 2000, driven by planet-warming emissions.

Let's speak to Roop Singh, Head of Urban and Attribution at the Red Cross Red Crescent Climate Centre.

Her team helped develop the report.

Thank you for coming on the programme.

Absolutely.

So just talk us through the headlines here.

Yeah, so the heatwave that we saw in Central America and North America is just evidence of the climate change that we're seeing around the world.

In our attribution study, we found that climate change made the maximum temperatures 35 times more likely, and the night-time temperatures up to 200 times more likely.

And that's really significant because it's really the night-time temperatures when your body is supposed to rest and recover that has impacts on human health.

And that's what's actually causing a lot of these heat-related deaths.

And just remind us of the mechanism here.

What is happening in what is heating what to lead to these temperatures?

Yeah, so we know that climate change is caused by increasing greenhouse gases, and essentially those greenhouse gases act to warm the planet around the world,

but they're also acting to sort of supercharge weather systems.

So we're starting to see these heat domes and essentially heat stick around for an extended period of time in different parts of the world.

We saw that in Mexico and Central America, and we're also starting to see that now in the northern and eastern parts of the United States.

So you said heat dome there.

Just expand on that a little for us.

What is it?

Yeah, absolutely.

So essentially, it's an area of high pressure.

It's a place where you have not a lot of clouds, not a lot of rainfall, but essentially, you just have high temperatures that stick around for days and days.

And essentially the duration of that heat causes a lot of impacts both on infrastructure but also on people.

And people just aren't able to cope when it's hot during the day and at night continuously for days on end.

So people are going to have to try and adapt now.

Is it possible, before we get on to adaptations, is it possible to predict where and when this is going to happen?

So we have heatwave early warning systems, and we have typically, lots of warning before a heatwave occurs.

And so in most parts of the world we are able to predict what the maximum temperatures are going to be days in advance,

and therefore, it actually is a big opportunity for us to be able to use that information to reduce the impacts, to warn people in advance of the heatwaves.

Okay, so if the warnings could be in place, what then?

What can people actually do?

What should governments actually do?

So there's individual actions, so essentially, cooling yourself, making sure that you're drinking water, cooling your home, so passive cooling technologies,

shading your homes, making sure you're planting trees outside, or just closing the shades when it's really hot is what people can do.

But then you also have organisations like the Red Cross, where we're providing first aid for people who are affected by heat stroke, for example, helping people recognise the signs of heat-related illnesses and take action before it's too late.

And then of course, cities and governments can work together to develop heat action plans, and that means essentially knowing what they're going to do, what services are they going to provide when there is a heatwave.

Are they going to open up a cooling centre?

Are they going to distribute water, ensuring that people have adequate access to electricity, which they need in order to cool their homes during a heatwave.

Roop Singh, thank you very much for coming on the programme, thank you.

Thanks.

Right, we're going to take a closer look at what's happening with the weather in the United States.

Now our correspondent, Nami Iqbal, is in Washington DC.

Hi Nami, just talk us through what's happening.

Well, Lewis, today is officially the first day of summer, and what a start.

You've got more than a quarter of the population that's under an excessive heat advisory, and generally 135 million people are impacted.

And temperatures have hit more than 90 degrees Fahrenheit, and are expected to go well over 100 from the Ohio Valley to the Mid-Atlantic, right up to New England.

I mean, Maine, if you think about that, that's the easternmost state in the US, doesn't usually get excessive heat, but it's thought that records will be broken there.

And in some parts on the East Coast, like New York City, school is out for some, a lot of schools closed up today to let children go home early, because of the excessive heat.

Over on the West Coast, we're seeing these wildfires break out, and it's worth mentioning that this happens, but it's happening more frequently, with more ferocity.

Two people were killed in New Mexico.

You know, we heard that some of the advice that's been given, and generally the advice is,

especially for vulnerable people, children, the elderly, those who work outdoors, especially here, you see them like a lot of construction workers in DC, to just really look after yourself, seek shade, make sure you drink lots of water.

Here in DC, it's about 90 degrees Fahrenheit.

There is some cloud cover, so it doesn't feel as sort of stuffy and swampy and stifling as it has been in the past few days,

but the temperatures here are expected to hit over 100 degrees Fahrenheit during the weekend, and there will be some respites.

A meteorologist reckoned that the temperatures might dip low, but then they will come right back up again next week and onwards.

And Nami, given everything you've just talked about there, has this seeped into the political discourse?

Any reaction from authorities?

Well, it's usually the same sort of messages that we get, is just keep safe as much as you can.

You know, it's kind of sort of follow the common sense advice,

but as I mentioned, for those who are in a certain group: childdren, the elderly, those who work outside, need to work outside all day, just manage that, you know, drink as much water as possible, get shade where you can.

There are like lots of trees around here in DC, you know, we're sort of standing under one so we can get some shade, but just try and look after yourself in that way.

There are also those vulnerable people who take certain kinds of medicine that you really can't regulate in this kind of heat.

So it's, you know, warnings for them as well.

So that's just generally the advice.

Look, it always gets hot in DC, I have to say, you know, I've been here for a few years and every summer it's really, really hot.

I think this, the prediction is that it's going to get much, much hotter.

So just, you know, really heed that advice.

Nami, thank you so much for that.