AMNA NAWAZ: Well, fall temperatures are finally cooling down for much of the U.S., but this past season was yet another reminder that the climate is changing.

2026 was the warmest summer on record in the contiguous United States.

Stephanie Sy reports on how some cities are considering whether residents should have a right to air conditioning.

It's part of our ongoing series Tipping Point.

STEPHANIE SY: This past July, as the nation celebrated a milestone Independence Day, New York City was sweltering under a record-breaking heat wave.

BRIANNA STYLES, Brooklyn Tenant: It was humid, hot, moist.

I felt like my apartment was melting.

STEPHANIE SY: Twenty-two-year-old Brianna Styles and her toddler suffered through it without air conditioning.

At one point, her Brooklyn apartment got so hot, she said the paint started peeling.

BRIANNA STYLES: The first day, we had to thug it out.

We were laying in this apartment.

I was doing TikTok hacks.

MAN: Absorb some of the heat.

BRIANNA STYLES: I was trying everything to cool us down.

I kept putting him in the bathtub with cold water, cold water.

But then the day after, I had some family friends help me.

They allowed me to stay in their home.

It kind of hurt me.

I'm like, oh, yes it's really hot.

I can't provide my son with cold air.

STEPHANIE SY: Unemployed and unable to afford a window A.C.

unit in her city subsidized apartment, Styles is among the nearly 10 percent of New Yorkers without access to A.C.

in their homes.

In some lower-income areas of the city, almost a quarter of households go without.

BRIANNA STYLES: My son had a really bad heat rash.

And not only that, he was also getting eaten by mosquitoes.

And I am waking up and I'm seeing my son with almost 100 bites every morning, and I didn't know what to do.

And it's like, I can't just close the windows.

And it was just -- it was very hard.

It was very hard.

LINCOLN RESTLER, New York City Council Member: Five hundred and eighty people die every single year in New York City from extreme heat, and the most common factor among them is that they lack access to cooling in their homes.

STEPHANIE SY: Starting in 2030, a new law will require New York City landlords to provide cooling systems capable of keeping rooms where tenants sleep at 78 degrees during the peak summer months.

Most tenants will be on the hook for the energy they use, but the city's public housing authority is largely exempt from the cooling mandate.

CALEB SMITH, WE ACT for Environmental Justice: Maybe we are using air conditioning, but we're using it more strategically.

STEPHANIE SY: Caleb Smith is the New York City policy manager for WE ACT for Environmental Justice in Harlem.

Smith says the law addresses New Yorkers' basic needs in a warming world.

Researchers estimate that, by the 2050s, New York City could have eight times as many days at or above 95 degrees due to climate change.

CALEB SMITH: If there's no baseline for what is acceptable in our housing for extreme heat, then it's always considered to be a luxury.

We already have requirements for heating because we know that no one should be freezing in their home.

And the same should apply when we're facing temperatures that have a heat index of 100, 105 degrees.

STEPHANIE SY: New York City is not alone in taking action.

Cities like Phoenix, New Orleans, and Dallas have cooling requirements on the books.

And, this summer, both Spokane, Washington, and Houston passed measures, mandating a so-called right to A.C.

for renters.

GRACE WICKERSON, Federation of American Scientists: We see policies popping up all over the country.

STEPHANIE SY: Grace Wickerson studies the intersection of climate and health at the Federation of American Scientists and has tracked the growth in these measures.

GRACE WICKERSON: Chronically high temperatures at night make it harder for you to sleep.

They make your body work harder to circulate blood throughout your system as a cooling strategy.

And all of these stressors compound.

And we're just starting to identify the many ways that heat then leads to heart attacks, kidney failure, and other health impacts that might not be -- quote, unquote -- "heat-related" at first glance, but are actually because we're seeing this compounding exposure work on people's bodies.

STEPHANIE SY: But in New York City, many landlords are against the new requirement.

KENNY BURGOS, CEO, New York Apartment Association: Putting the burden on property owners is not the right way the government should be approaching this.

STEPHANIE SY: Kenny Burgos runs the New York Apartment Association, which represents thousands of rent-stabilized property owners in the city.

About 40 percent of New York's housing stock is in this category, where rent increases are restricted by a municipal board.

KENNY BURGOS: New York City building owners and particularly rent-stabilized property owners are operating some of the oldest housing in the city of New York, and they have been running up against just increasing operation costs.

We have seen an explosion in insurance costs.

We have seen property taxes rise.

We have seen water and sewer rates rise year over year.

And now you add in what we call unfunded mandates from the city council, this A.C.

bill.

STEPHANIE SY: Burgos also points to infrastructure concerns, including whether older buildings and the city's electrical grid can handle tens of thousands of new A.C.

units.

Adding A.C.s may also conflict with existing city laws to reduce climate change because they add to carbon emissions.

But advocates argue that a right to A.C.

should be paired with subsidies for more efficient devices and weatherization to reduce the carbon impact.

CALEB SMITH: All of the investment towards energy efficiency means essentially that people use less energy to cool their homes down.

STEPHANIE SY: But paying for that energy can be a big hurdle for tenants.

DIANA HERNANDEZ, Columbia University: The provision of an air conditioning unit is a first step.

It's a necessary step, but it is inadequate.

We do need probably kind of bill supplements, need utility discounts, additional energy assistance.

STEPHANIE SY: Diana Hernandez is a public health professor at Columbia University and co-author of the recent book "Powerless: The People's Struggle for Energy."

Her 2024 research shows that one in five New Yorkers had difficulty paying utility bills.

DIANA HERNANDEZ: In Arizona, 75 percent of indoor deaths are happening in homes that have an air conditioning unit.

So we know that people are dying, not necessarily because they lack air conditioning units, but because they are reluctant to turn those air conditioning units on.

NARRATOR: Summer can mean dangerously high heat.

STEPHANIE SY: Hernandez points to the need to expand supports like the Low Income Home Energy Assistance Program, which has not kept up with inflation.

The Trump administration has proposed cutting the $4 billion program entirely.

DIANA HERNANDEZ: People will face the risk of a disconnection.

And in many states, there aren't many protections, particularly in hot weather months.

STEPHANIE SY: Brooklyn tenant Brianna Styles applied to a state program for a free A.C.

this summer, but never heard back.

But if she were able to get a unit, she knows it would increase her electric bill.

BRIANNA STYLES: That's something I have to worry about and 100 percent that's something I need.

My child cannot be in the boiling heat.

Like, he's a kid, and he shouldn't have to go through that.

STEPHANIE SY: Would it also be a sacrifice?

Would it keep you from being able to pay for other things?

BRIANNA STYLES: A hundred percent, but nothing is worth my son going through any type of pain.

STEPHANIE SY: In New York City, summer is officially over, but extreme weather isn't going anywhere.

For the "PBS News Hour," I'm Stephanie Sy.