Photo/IllutrationHirakata Park in Hirakata, Osaka Prefecture (Asahi Shimbun file photo)

HIRAKATA, Osaka Prefecture--A 28-year-old man died from heatstroke at an amusement park here on July 28 after dancing in the sweltering heat dressed in a mascot costume, police said.

Police on July 29 said they are investigating the circumstances of his death.

The part-time worker at Hirakata Park in Hirakata, Osaka Prefecture, started practicing for a dance performance at the attraction at around 7:30 p.m. on July 28 on an outdoor stage with 10 or so other staff members.

The man was wearing an outfit weighing about 15 kilograms to play the role of a fairy character “who lives in the park,” according to police.

After the rehearsal, he lost consciousness. He was rushed to a hospital, but was pronounced dead there soon after, police said.

The temperature was 28.7 degrees as of 8 p.m. in the city on the day, according to the Osaka Regional Headquarters of the Japan Meteorological Agency.

"We would like to offer a deep apology from the bottom of our hearts," Keihan Leisure Service, the park's operator, said in a statement. "We will find the cause of it and work to prevent it from happening again.”

The park said it will suspend performances using character outfits for the time being.