Dozens of Donald Trump’s supporters have been requiring medical help at his rallies in the scorching US southwest but it seems lost on him that his plans to reverse climate policies and “drill baby drill” for fossil fuels will only worsen extreme weather, campaigners say.

A total of 24 people at a Trump rally in Las Vegas on Sunday required medical attention due to the heat, according to the Clark county Fire Department, with six taken to hospital for treatment. The hospitalizations come after a further 11 people needed to be admitted to hospital for heat exhaustion as they waited for Trump to speak at a rally in Phoenix on Thursday.

Trump himself noted the severe heat during his speech on Sunday, with the Las Vegas rally starting around noon where the temperature was around 90F (32C) and climbed to around 102F (38C). The rally was held in a park with little shade, although organizers provided water and cooling tents, and allowed attendees to hold shading umbrellas.

“It’s 110, but it doesn’t feel it to me,” said Trump, who wore a suit jacket and signature red baseball cap. “I’m up here sweating like a dog. They don’t think about me. This is hard work.”

Trump then said: “I don’t want anybody going on me. We need every voter. I don’t care about you. I just want your vote. I don’t care.” He later said he was joking about not caring about his own voters and complained the media would criticize him for this.

Record-breaking heat enveloped much of the US southwest last week, with temperatures soaring beyond 110F (43C) in areas stretching from California to Arizona. Roughly half of Arizona and Nevada were under and excessive heat alert, even though the official start of summer is still a week away, with Las Vegas hitting 110F on Friday and Phoenix reaching 113F (45C).

Scientists have found that heatwaves are moving slower and lasting longer due to the climate crisis, which is primarily caused by the burning of fossil fuels. Studies last year concluded that the searing heat experienced in Europe and the US would’ve been virtually impossible without the influence of human-caused global heating.

Trump has vowed to accelerate oil and gas production, already at record levels, in the US, however, repeating the mantra “drill, baby, drill” at rallies. The former president and newly-convicted felon aims to undo Joe Biden’s policies aimed at lowering carbon emissions, which he has called “insane”, and has directly sought $1bn in campaign donations from oil and gas executives in order to fulfill this agenda as president.

“Donald Trump is openly telling people that he’s only out for himself,” said Alex Glass, a campaigner at Climate Power, a climate advocacy group. “He’s making promises to Big Oil executives who are fueling the climate crisis while people are passing out at his rallies from very real, very dangerous heatwaves that he says are caused by a hoax.”

The dangers of worsening heatwaves did not give pause to Trump’s backers sweltering in Las Vegas, however. “This is a dry heat – this ain’t nothing for Las Vegas people,” said Michael McDonald, Nevada’s Republican party chair, who added that it “symbolizes for the rest of the United States we will walk through hell” to elect Trump.

“You know what? It’s worth it,” Camille Lombardi, a 65-year-old retired nurse from Henderson, in suburban Las Vegas, who was seeing Trump in person for the first time, told AP. “Too bad it wasn’t indoors, but that’s OK.”