LAS VEGAS » Chelsea Patricia Ake-Salvacion liked working at a Las Vegas cryotherapy center so much that she stayed behind when her boyfriend moved back to Hawaii and posed for promotional photos featuring a small chamber bubbling with a cottony cloud of liquid nitrogen, her uncle said.

The 24-year-old was passionate about the treatment that subjects users to sub-zero temperatures for a minute or two to relieve pain and other conditions.

She planned to spend another year working at Rejuvenice Cryotherapy before opening a similar business of her own in the islands, her uncle, Albert Ake, said Tuesday.

"She was a good spirit and loved everyone," Ake said. "She had the true aloha spirit. Aloha is love."

But something went wrong when Ake-Salvacion went in for her own treatment last week, leaving her dead alone inside the chamber the size of a phone booth.

She had texted her boyfriend that she was taking a treatment herself after the store closed, Ake said. She also was seen on security video locking the salon, he said.

She was found dead the next morning, Oct. 20, after a co-worker arrived and noticed Ake-Salvacion’s car in the parking lot and her belongings in the business.

"When they found her, she was rock solid frozen," the uncle said in a telephone interview from his home in Reno.

What killed Ake-Salvacion hasn’t been determined. But her death pointed to possible dangers in an increasingly popular but largely unregulated treatment favored by celebrities and sports stars. Athletes who have long used ice baths to ease their aches have turned to whole body cryotherapy as a quicker way to recover after exercise or competition.

Police found nothing suspicious, and the police case was closed without a criminal investigation. The Clark County coroner said determining Ake-Salvacion’s cause of death will await the results of toxicology tests in coming weeks.

Nevada Occupational Safety and Health investigators said Ake-Salvacion should not have been using the cryotherapy chamber after hours for personal use, agency spokeswoman Teri Williams said.

"The facts indicate that the fatality occurred as a result of employee misconduct or non-compliant activity," Williams said. "The employer cannot be cited … and further investigation is not warranted."

Nevertheless, two company locations in Las Vegas and unincorporated Clark County were ordered closed Tuesday, after authorities said they found no business licenses and no company permit to perform cosmetic or other procedures.

State regulators said the owners also didn’t provide required proof of worker compensation insurance.

Attempts to reach spa owners Christian Chateau and Kevin Goujon weren’t successful.

The company had plans to open a third location, said Williams, who also represents the Nevada Department of Business and Industry and the state Division of Industrial Relations. She said all three locations were slapped with a stop-work order.

The moves by the city, county and state came a day after the Nevada State Board of Cosmetology ordered the spa where Ake-Salvacion died shut down for not having a license to perform skin and other advertised aesthetician services such as facials. The owners were fined $1,000.

"We didn’t even know who they were," Gary Landry, cosmetology board executive director, said about the spa owners. "They had never approached us."

Rejuvenice booked 30-minute sessions for $60 through an Internet discount that put regular prices at about $100.

Besides curbing pain, the treatment also is promoted as aiding weight loss, improving healing and increasing blood circulation, leading some salons to offer cryotherapy facials as an anti-aging remedy.

Associated Press researcher Jennifer Farrar in New York contributed to this report.