Sunmi's agency, Abyss Company, released Sunmi's concept photo of "열이올라요 (HEART BURN)" on its official SNS channel on June 21st today. The released photo shows Sunmi's colorful appearance with her orange hair her.

Sunmi created a fresh and refreshing atmosphere in front of roads, grass, and fountains against the backdrop of the hot sun in LA. In particular, she showed off her innocent visuals with fluttering hair and braided hair.

The last concept photo, which is staring at the camera with an expressionless face, created a dreamy atmosphere with intense eyes, raising more curiosity about the concept of the new song.

Earlier, Sunmi released a track list image on June 20th. According to the tracklist image, the single contains two songs, "열이올라요 (HEART BURN)" and "풋사랑 (CHILDHOOD)." Sunmi participated in writing the lyrics of the new single and title song "열이올라요 (HEART BURN)" of the same name and wrote and composed the song "풋사랑 (CHILDHOOD)" to capture her unrivaled musicality.