FIRST ON FOX: Sen. Roger Marshall, R-Kan., gave assistance to a migrant suffering from heat exhaustion on a recent dramatic trip to the southern border – an incident that he said was a window into the "unsustainable humanitarian crisis" at the U.S.-Mexico border.

Marshall, a physician, was on a trip to the border in Texas, along with sheriffs from Kansas and was riding along with Brooks County, Texas, sheriffs in an area between where smugglers drop off illegal migrants, and where they are picked up by others. It’s a hazardous area with treacherous conditions for migrants who have often traveled thousands of miles.

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"This is rough wilderness," Marshall told Fox News Digital in an interview, noting the risks of rattlesnakes, the Texas brush and the heat. "It’s hot already down there."

Agents spotted a human smuggler pull up to an area, bring four or five people into the car – as well as one in the trunk. Agents gave chase until the car pulled over and the inhabitants fled. 

Agents caught many of those fleeing, including one woman who Marshall said was showing severe symptoms of heat exhaustion that had the potential to turn deadly. It was then that he stepped into action.

Sen. Roger Marshall at the southern border

Sen. Roger Marshall gives aid to a distressed migrant at the southern border.

"The one young lady was obviously having heat exhaustion, and maybe she was bordering on heat stroke so when they brought her I was able to look at her, and …her respiration was really fast, her pulse was 140, she hadn’t drunk water in two days, her knee was hurting, her hand was cut up from the barbed wire fence, and I really think she’d have probably died in, I don’t know, an hour or two."

Video issued by Marshall’s office shows the M.D. giving her water, examining her wounds, and helping to carry her to a cooler area and calm her breathing.

"We got her cooled down, got water to her, just basic first aid, so that's what you’re seeing me attend to her health needs," he said.

While heat exhaustion is not uncommon at the border, the risk of that developing into heatstroke is significant.

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"I don't get intimidated by situations and when they brought her back over the fence and I saw her breathing as she was I knew she was in distress, the agent yelled for help, and she was semi-conscious, fading in and out. That’s heat exhaustion going into heatstroke, and once heat stroke starts, it's almost irreversible," he said.

Despite him stepping up to help, he emphasized that Border Patrol agents, who do this work and tackle these conditions every day, are the heroes of the story.

"Those poor officers are expected to be nurses, social workers, psychologists and at the same time have to keep themselves safe and keep America safe," he said. "I was able to do my little part, but they're the true heroes, not me."

Marshall said that the incident showed the "unsustainable humanitarian crisis" at the border that affects not only Americans but the migrants themselves, who have often traveled hundreds of miles on foot and can be exploited by trans-criminal organizations.

"So by the time they show up they have dysentery, they're dehydrated, they have wounds, infections, many of them have been sexually abused, all the things you can imagine, and then many people are dying on the way from the heatstroke, from dehydration and then more dying as they drown coming across the river," he said.

He put the blame squarely on the policies of President Biden and said the agents had told him that what they need is to get back to the policies of the Trump era, including finishing construction of the border wall.

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"This is an unsustainable humanitarian crisis, this is a human tragedy created by Joe Biden and his policies," he said. He wants this crisis, either he’s the most incompetent person in the world, or he wants this crisis – he wants to remake America."

He also called on Biden to visit the border himself.

"He needs to go see what I saw, not fly into a little airport there and say, ‘I went to the border’ like the vice president. Joe Biden needs to go see the crisis he’s created."