The Angel Valley Sweat Lodge in Sedona, Ariz., after 2 died and several others were sickened.
Two people are dead and several others remain hospitalized Friday after becoming mysteriously ill in a sauna-like sweat lodge at an Arizona resort.
Three people had heart attacks and about 21 in all were treated for injuries after being sickened Thursday night at the Angel Valley Sweat Lodge in Sedona. Two died.
The resort is next to GOP Sen. John McCain's ranch, according to MyFOXPhoenix.com.
Emergency crews responded about 5 p.m. Thursday to a hazardous materials situation at the sauna, the station said. Three patients were reportedly suffering cardiac arrest when ambulances and a helicopter arrived.
About 50 people were in a "sweatbox"-type structure when they were overcome at the resort, which provides Native American-style spiritual retreats, Yavapai County sheriff's spokesman Dwight D'Evelyn said Friday.
Many people began feeling ill after about two hours in the sweat lodge.
About 21 people were taken by ambulance or helicopter to area hospitals, where two were pronounced dead, D'Evelyn said. The dead were only identified as a man and woman, both middle-aged.
Two people taken to Flagstaff Medical Center were listed in critical condition on Friday. Three others who were admitted to a hospital in nearby Verde Valley recovered quickly; two were released overnight and one was reported in good condition on Friday.
Sheriff's homicide investigators were working to find the cause and determine if any criminal actions might have been a factor in the incident, D'Evelyn said. Investigators remained at the resort and were interviewing the retreat director, staff and resort guests on Friday.
Sedona is a resort town about 115 miles north of Phoenix famous for its red rocks. It is well-known as a center for a modern spiritual movement. Sweat lodges are indoor saunas usually located at spiritual resorts.
The Associated Press contributed to this report.