Some of the ways extreme heat will change life as we know it

Life as we know it could soon change if extreme, dangerous heat continues to inundate regions for longer stretches of time and at higher temperatures, according to experts.

A large part of the U.S., including much of the southern portion stretching from the West Coast, across Texas and to the Southeast, has been experiencing triple-digit temperatures and heat indexes for weeks on end.

Record-breaking temperatures have been the norm in several cities in recent weeks, including Phoenix, which has now seen more than 40 consecutive days at about 110 degrees.

Hotter-than-ever temperatures, and longer periods of time when they occur, will become the norm unless greenhouse gas emissions are drastically curbed, mitigating further global warming, according to climate scientists. Americans could see an average of 53 more days of extreme heat by 2050, if emissions aren't reduced, according to climate modeling data released by the ICF Climate Center in June.

The increased heat is guaranteed to alter how society operates, experts told ABC News.

How kids spend their summers

Summer is synonymous with time spent outdoors for school-aged children all over the world.

But parents may be cautious about letting their kids spend prolonged periods of time outdoors when temperatures are nearing triple digits, especially if air quality is poor or UV indexes high, experts told ABC News.

"The great outdoors go from being a magical place of exploration to a threatening place, full of fear," Lise Van Susteren, a general and forensic psychiatrist who has researched how climate change has affected the psychological health of young people, told ABC News.

Less time outdoors could also be detrimental for children's development. Research shows outdoor time is linked with improved motor development and lower obesity rates and nearsightedness in children. Outdoor play also promotes curiosity, creativity and critical thinking and is linked with behavior displaying less anger and aggression, studies have shown.

Few things could be more injurious to a child's development than to be cooped up inside year-round, Van Susteren said, adding that humans have evolved to find the sounds and sights of nature meaningful and necessary for a healthy outlook.

"Yeah, you could always build something artificial. But don't expect it to do for us mentally, which includes our ability to empathize and be generous, and to feel a sense of adventure," she said.

Evidence that being holed up indoors is detrimental to kids' mental health surmounted during the COVID-19 pandemic, which added more to the preexisting psychological distress among young people, according to the U.S. Surgeon General.

Athletes may alter their training

Athletes of all ages and levels will likely need to alter their training to stay safe during extreme heat, but those training for intense competitions that take place in a scorching climate need to be especially careful, said Brian Maiorano, coach liason for Core, a wearable tech that allows athletes to measure their core body temperature on the go.

Those training for competitions and races will need to adapt to the higher temperatures in order to participate safely, said Maiorano, who has coached athletes for running competitions and triathlons for 15 years.

"The human body is extremely adaptable, if given the right training," he said.

Rather than training indoors in a climate-controlled setting, athletes will need to train outside and get their core body temperature to a level that will cause physiological adaptions, Maiorano said. Otherwise, athletes will suffer on race day.

Temperatures in the 90s are considered extreme for endurance athletes, while temperatures in the 80s would be considered extreme for those training for an event with even more difficulty and physical exertion, like the Ironman Triathlon, Maiorano said. About 80% of the heat in the body is generated by the power in the muscles, he said.

"It's like literally having a space heater inside of you," he said.

Up until a few years ago, heat training was an "imprecise practice," Maiorano said.

People training for events in warm climates -- like the Hawaii Ironman and the Western States Endurance Run, which is a 100-mile race through the desert in California -- were likely told by their coaches to go out during the hottest part of the day while wearing multiple layers of clothes.

"Cook yourself, but don't overcook yourself, which is some really vague guidance," Maiorano said. "It's guidance you can give to a top athlete and hope that they don't cause themselves heatstroke, but it's not something that you can tell an age group athlete to do."

Peak travel seasons and destinations will change

Extreme heat will affect travel decisions people make in the summer, the peak travel season while kids are out of school, Erika Richter, spokesperson for the American Society of Travel Advisers, told ABC News.

"The climate crisis will impact where we go, when we go, and, in some cases, if we go," Richter said.

The travel industry is already seeing shifts for travel to Greece, France and Spain, Richter said. While the peak tourist season is typically around July, Europe has been reaching record temperatures in recent years during that time. Combined with wildfires, the climate is causing people to travel to those destinations in the spring or early summer instead, Richter said.

People are also starting to choose cooler places for the summer travel season, such as Northern Europe, Alaska and the Pacific Northwest, Richter said.

Extreme heat is also heavily affecting air travel.

It is difficult for planes to take off in hot temperatures because as the air warms, it expands, so the number of molecules available to push the plane up is reduced. In June, Richter experienced a six-hour delay on a flight from Washington, D.C., to Portland because the plane could not take off with the number of passengers, she said.

While some passengers took the $1,000 credit offered to give up their seat, the originally nonstop flight had to stop in Missouri to refuel, because the plane could not handle the fuel load needed for the transcontinental flight, Richter said.

Extreme heat can also increase the amount of turbulence passengers experience. A 2017 study found that climate change may cause nearly three times as much clear-air turbulence as current conditions by the period between 2050 and 2080. Clear-air turbulence, which occurs without a visual warning like clouds or thunderstorms and is usually at high altitudes, is currently on the rise worldwide and at varying altitudes, the study found.

There have been several reports of heavy turbulence this summer, including a Hawaiian airlines flight in July that injured several flight attendants and passengers.

The wildfires in Canada, which have been so severe this season in part due to higher temperatures and drought, have impacted travel in the U.S., Richter said.

With more heat and humidity comes the possibility of thunderstorms grounding flights, as well, Richter said.

"We're used to the thunderstorms for summer travel season," she said. "But they are becoming much more violent, and they are grounding many more flights."

Reliance on air conditioning will increase

As climate change continues to worsen, regions that traditionally did not need air conditioning may need to brace for more heat waves by installing equipment to keep their homes cool.

In places like the Pacific Northwest and the San Francisco Bay Area, the majority of households are not equipped with central air conditioning. In 2021, when a historic heat wave struck the region, window and portable air conditioners were flying off the shelves, Jennifer Amann, senior fellow of the American Council for an Energy-Efficient Economy's building program, told ABC News.

Incorporating efficient cooling methods, like using the same pumps that heat homes to cool them, as well, and using efficient window air-conditioning units, will help households keep temperatures bearable in their homes, Amann said,

Heat is the No.1 weather-related killer, with more than 600 people dying from heat-related illnesses every year in the U.S., according to the Centers for Disease Control and Prevention. When temperatures do not cool down overnight, it exacerbates the risk to human health.

Buying an air conditioner is the short-term solution, but people will also need to adapt their homes to better deal with extreme heat, and builders will need to design new homes with more passive mechanisms to navigate the changing climate, Amann said.

The economy could suffer

Extreme heat is taking a toll on economies in countries all over the world.

Countries in Europe like France, Italy, Spain, Romania and Germany have been the most affected by climate-related disasters over the past 20 years, an analysis by the Centre for Economic Policy Research found.

Domestically, Texas loses an average of $30 billion a year due to its climate and the large number of people working outdoors, according to a 2021 report by the Adrienne Arsht-Rockefeller Foundation Resilience Center, a Washington, D.C.-based think tank.

The cumulative global economic loss between 1992 and 2013 reached between $5 trillion and $29.3 trillion due to the impact of human-caused heat waves, according to a study published in 2022 in Science Advances.

The poorest countries in the hottest climates suffered the most, researchers found.

Heat also affects people's moods, which is essentially survival mode kicking in, Van Susteren said.

"If we're in a bad mood, we're not buying," she said.