Hungary isn't just sweating through a summer heatwave. It's in the middle of an air conditioning boom – one that's transforming homes, classrooms and careers.

On the top floor of a Budapest apartment building, Ferenc Pallai installs yet another AC unit. 

"We're putting in the fourth unit today in this building," he says. "All the tenants were complaining about the heat, so we've been here working for a week to get them units."

Pallai owns Master Cool Klimatechnika. His crews used to work mainly in summer. Now, they're booked months ahead. 

"We've been really busy these past few months," he says, "and we're already booked even after summer. I think we'll stay busy at least through October."

Much of the demand is for low-cost, dual-purpose AC units that also heat. Most are made in China, though some come with European branding. 

"The most common and popular brands are usually Chinese," Pallai says. "There are also others that look European because of their logo, but they're actually Chinese units rebranded by European companies."

But hardware is only part of the challenge. Hungary also needs people trained to install the systems.

At Ezkimo Academia, Karoly Marton trains an ever-growing number of HVAC (heating, ventilation and air conditioning) technicians. 

"The number of students has definitely gone up," Marton says. "It's become a really in-demand profession. 

"These days, every building needs to have air conditioning. It wasn't like that before. AC used to be a luxury – now it's standard. That shift has made more people want to learn the trade."

Marton isn't just training young graduates. His classrooms include people switching careers – even artists and engineers. 

"It's not uncommon to have IT people, former violinists, people from all different backgrounds studying to become technicians," he says.

The training is fast. A student can be certified in about three months – and can start to make money fast.

"A good climate technician can earn in a few days the money that the average person earns in a month," Marton says.

But the growing number of AC units comes with a price: electricity. Summer demand in Hungary has hit record highs. Still, the grid is adapting. Solar now supplies about a quarter of the country's power. New regulations are boosting battery storage to help meet peak demand.

A cool home. A new profession. And a country adjusting to rising temperatures – one wall unit at a time.