The 53-year-old arrived in the badly hit coastal state of La Guaira shortly after the magnitude 7.2 and 7.5 earthquakes struck within a minute of each other on June 24.

More than 6,500 people were killed, while an unknown number of victims are still believed to be buried beneath collapsed buildings.

For Pacheco, the search has taken both a physical and emotional toll. After one exhausting day digging through debris, he struggled to breathe and briefly lost consciousness.

“The oxygen was slowly taken away from me until I kind of lost consciousness,” Pacheco told AFP.

“Everything went blurry and I thought of my young son before asking myself, ‘What’s going on?’”

When Pacheco first arrived in La Guaira, he immediately joined efforts to find a little girl trapped beneath a collapsed social housing complex.

He also remembers hearing a family trapped on the top floor calling for help.

“There were people screaming, asking us to help them,” he said. “I went where I was needed.”

Pacheco works with the Unified Rescue Group of Venezuela, or GRUV, a volunteer organisation that relies on donations. The group has rescued 21 people alive and recovered 56 bodies.

Pacheco said watching families continue waiting for loved ones still buried beneath the rubble has “profoundly impacted” him.

Authorities have not provided an official figure for the number of people who remain missing.

“When to close this chapter?” Pacheco asked.

“God willing, as soon as possible, so that everyone, so that those family members too, can find relief from the suffering they are going through, from not being able to recover their loved ones.”

Among those who have witnessed the rescuers' work is Frank Viloria, whose sister and niece died when their eight-storey building collapsed in Playa Grande.

“When I see him, I’m happy,” Viloria said after meeting Pacheco again.

“I’m very grateful to them. I feel a lot of respect and admiration; I can vouch for them because I saw how they work,” the 38-year-old added.

La Guaira, normally a popular weekend destination for people from Caracas, has been transformed since the earthquakes. Thousands who lost their homes are now living in makeshift camps.

For Pacheco, leaving the disaster behind has proved difficult.

“Sometimes I’m very sad; my mind is here... it’s never at home” in Caracas, he said.

“We’re going to keep going for as long as the body allows,” Pacheco said.

Life at extreme altitude is not limited to remote mountain villages. Some of the world's highest permanent settlements are home to hundreds of thousands, and in some cases more than a million people , who have adapted to thin air, freezing nights and reduced oxygen levels.

Leading the list is La Rinconada in southeastern Peru, the world's highest permanent settlement at approximately 5,100 metres (16,732 feet) above sea level. Located near the Ananea gold mines in the Andes, the town grew rapidly because of informal gold mining despite lacking many basic public services. Encyclopaedia Britannica and scientific studies describe it as one of the harshest places on Earth to live, where oxygen levels are roughly half those at sea level.

Bolivia is home to three of the ten highest settlements on the list.

El Alto, at around 4,150 metres, is the world's highest major city and one of Bolivia's fastest-growing urban centres. According to Encyclopaedia Britannica, it has grown into an economic hub linked directly to neighbouring La Paz through highways and one of the world's highest urban cable car systems.

Nearby Potosí, sitting at about 4,050 metres, was once among the richest cities in the world after vast silver deposits were discovered at Cerro Rico in the 16th century. During the Spanish Empire, its mines supplied enormous quantities of silver that helped finance Spain's global ambitions.

Although often regarded as Bolivia's capital, La Paz is the country's administrative capital and lies at around 3,650 to 3,870 metres, depending on the district. Government offices are located there, while Sucre remains Bolivia's constitutional capital.

Living above 2,500 metres presents significant physiological challenges. The World Economic Forum notes that lower oxygen levels reduce physical performance for newcomers, while long-term residents often develop genetic and biological adaptations that improve oxygen transport.

Research published in scientific journals and summarised by IFLScience shows that populations in the Andes, Tibetan Plateau and Ethiopian Highlands have evolved different adaptations over thousands of years. Tibetans, for example, have genetic traits that allow more efficient oxygen use without producing excessive red blood cells, while many Andean populations tend to have higher haemoglobin concentrations.

China's Lhasa, standing at approximately 3,650 metres, is the historic capital of Tibet and home to the Potala Palace, a UNESCO World Heritage Site that served for centuries as the residence of the Dalai Lamas.

Peru's Cusco, at roughly 3,400 metres, was the capital of the Inca Empire before the arrival of the Spanish and remains one of South America's most important historical cities.

Further north, Quito in Ecuador sits at around 2,850 metres on the slopes of the Andes. Its historic centre is one of the best-preserved colonial districts in Latin America and was among the first sites inscribed on UNESCO's World Heritage List in 1978.

Bogotá, Colombia's capital, stands at approximately 2,640 metres, while Addis Ababa, Ethiopia's capital, sits at around 2,450 metres and is often described as Africa's highest capital city. Asmara, the capital of Eritrea at 2,325 metres, is recognised by UNESCO for its exceptionally preserved Italian modernist architecture.

During an emotional meeting on Thursday, Cantillo embraced members of Mexico's Topos rescue team, thanking them for refusing to give up while he remained trapped.

Fighting back tears, he recalled how the rescuers stayed with him throughout the ordeal, offering water , encouragement and hope as they worked to reach him.

"You are the angels that God sent," Aaron told the rescuers as he hugged them one by one and thanked them for saving his life.

Cantillo was rescued after spending more than four days beneath collapsed debris following the powerful earthquakes that struck La Guaira on June 24.

According to the latest official figures, 2,595 people were killed and 12,400 others were injured after two earthquakes measuring magnitude 7.2 and 7.5 struck just 40 seconds apart.