The cooler on Tom Hensley and Tasha Brotherton’s decrepit trailer isn’t doing the job.

As temperatures approach 115 degrees Sunday, that’s not just annoying — it’s dangerous.

“I have asthma. Had it all my life,” Brotherton told me in the shade outside their home last week. “If I get overheated, that’s a trip to the hospital.”

But the manager of the south-side park where Brotherton and Hensley live says she has responded to every complaint they’ve made and fixed the cooler adequately. And when I measured the temperature Friday, it was 96 outside and 84 inside. Some cooling was happening.

It’s the kind of conflict that plays out routinely between landlords and tenants, though in this weather the stakes are higher. If the couple lived just a few blocks further south, they would have somewhere to turn to resolve their complaints.

This year, the city of Tucson’s code-enforcement division has responded to more than 20 complaints about rental homes having inadequate cooling. In some cases, city inspectors found that the cooler or air conditioner actually was working. In others, they found the owners in violation of city codes, compelling them to make repairs.

But the ABC Mobile Home Park, where Brotherton and Hensley live, is at 3870 E. Benson Highway, in a mile-wide swath of unincorporated Pima County that runs from about East Golf Links Road south almost to East Valencia Road. Back in the 1990s, when the city of Tucson tried to incorporate it, the area was known as the Palo Verde Corridor. It’s replete with mobile home parks, some in adequate condition, others run down beyond belief.

As my colleague Emily Bregel pointed out in her 2014 stories on dilapidated trailer parks, the county doesn’t have codes requiring minimum maintenance and conditions inside rental homes. State law does require cooling, along with running water, electricity and other basic utilities. But there’s no one at the state level to enforce those laws for people living in rental trailers.

The state’s Office of Manufactured Housing enforces the state Landlord-Tenant Act for mobile-home residents, but that set of laws doesn’t apply to people who rent their trailers.

Where does that leaves the many poor people in the Palo Verde Corridor, like Brotherton and Hensley? Out of luck.

A half-mile west at Desert Willows Mobile Home Park, I met Don Rankhorn, who was installing a new ignition in his Nissan Sentra. His family has rented an old trailer there since November. It has working air-conditioning units, but the trailer’s walls are uninsulated.

“It’s just metal. It gets hot,” Rankhorn said. “The summertime is what kills you.”

I asked whether these days it gets cool enough to sleep through the night. “In the middle of the night,’ he answered.

Across Arizona, most residents of mobile home parks own their trailers, renting the space underneath from the park owner. But many rent, and they are among our area’s poorest residents.

Often, as I’ve described in the past, renters are promised that they will get title to their trailer if they pay rent steadily for a year or two. These trailers are so old and run-down, in many cases, that they’re not worth more than a couple thousand dollars.

But often the owner doesn’t have the title, and nobody knows who the nearly worthless trailer really belongs to. In fact, owning the trailer can be worse than renting because it means the owner must pay a small property tax bill of perhaps $80 per year and, most importantly, maintain their own place.

When there are holes in the floor, when the cooler is defunct, or, as in Brotherton and Hensley’s trailer, when the circuit breaker is located beneath the kitchen sink, fixing the trailer can be an expensive proposition. Better to have a landlord maintain it.

But if there’s a dispute, the state of Arizona and Pima County leave the renters completely unprotected. There is an Office of Manufactured Housing, and I spoke with the director of the department that contains it, Debra Blake. She explained the office enforces Arizona’s mobile home landlord-tenant act, but that doesn’t apply to people who rent their trailers.

Southern Arizona Legal Aid takes up some cases on behalf of renters, but the demand for free legal help far outstrips the supply.

That leaves mobile-home renters in the run-down parks of the Palo Verde Corridor to fend for themselves. It’s risky to confront the landlords and managers, who could turn any conflict into an eviction order, leaving people with barely any shelter homeless.

At Desert Willows, Rankhorn and others told me they do many of their own repairs, even though they aren’t legally owners yet. And, to tell the truth, they may never be. Titles to these old trailers disappear and sometimes aren’t worth spending the money to obtain.

In the city, though, there is enforcement, as Mike Wyneken, the interim administrator of code enforcement explained.

“We spend a lot of time on these cases with these property managers, pushing them and pushing them to make the repairs that need to be made,” he said. “Depending on the situation, it could be a lot of money.

“These are tough calls because a lot of the people we deal with don’t have a lot of options,” he said.

At least, though, these renters have the option of calling the city. Brotherton, Hensley, Rankhorn and other renters in the unincorporated county don’t have that option. If it comes to a dispute, they’re on their own.

In this heat.