10-year-old boy dies in Arizona after hiking in triple-digit temperatures

A 10-year-old boy has died after he suffered a "heat-related medical emergency" during a hike in Arizona on Tuesday.

Firefighters from the Phoenix, Tempe and Chandler fire departments were called to South Mountain Park and Preserve around 2 p.m. local time, according to a release from Phoenix Fire. Phoenix Police Department said officers were called shortly later to Mormon Trailhead.

The boy had reportedly been hiking with relatives when he began to suffer the medical emergency.

Firefighters, technical rescue team members and police officers reached the boy, who was up about one mile on the trail, according to Phoenix Fire and Phoenix PD. The boy was airlifted from the trail to a waiting ambulance, where he was transported to the hospital in "extremely critical condition" before dying.

Phoenix Fire officials told local ABC News affiliate KNXV-TV that the boy's family may have been from out of town, but where is unclear.

Phoenix PD detectives are currently investigating the incident. The department did not immediately return ABC News' request for comment.

Temperatures in Phoenix reached a high of 113 degrees Fahrenheit on Tuesday, according to National Weather Service Phoenix in a post on X, about six degrees above the average temperature.

Heat is the leading cause of weather-related deaths in the United States, even though most are preventable, according to the Environmental Protection Agency. About 1,220 people die in the U.S. from heat-related illnesses every year, the Centers for Disease Control and Prevention said.

Normally during extreme heat -- meaning temperatures that are hotter and/or more humid than average -- the body tries to cool itself by sweating.

If a person does not replenish with fluids, it can lead to dehydration. The body temperature can then continue to rise and mild symptoms emerge such as sunburn, heat rash or heat cramps.

This can progress to heat exhaustion -- which includes symptoms of headaches, dizziness, muscle cramps, nausea and vomiting -- and, if the body reaches extremely high temperatures, heat stroke.

Anyone can be impacted by heat-related illness but some populations -- including the elderly, infants and young children, outdoor workers and people with low socioeconomic status -- are at higher risk.

To lower the risk of heat-related illness, the CDC recommends staying hydrated and remaining in an air-conditioned space as much as possible. If you go outside, the CDC recommends waring lightweight, loose-fitting clothing.