Authorities have released the names of the two children found dead in a sweltering car at a Topeka-area home Sunday. The victims are identified as 3-year-old Raylynn Gardner and her younger brother Kyler Gardner.

The Shawnee County Sheriff's Office says excessive heat killed two 3-year-old siblings who were found in a family car.

Investigators said Tuesday that the girl and boy died of hyperthermia.

Officials said both children were healthy and no other factors contributed to their deaths.

They were found in an unlocked but closed car Sunday afternoon in the driveway of the family home south of Topeka.

Although the outside temperatures were in the mid- to upper 70s on Sunday, a Shawnee County coroner said temperatures inside the car could have been around 120 degrees.

The children's mother reported them missing Sunday afternoon, and investigators later found them in the car. The sheriff's office said the investigation is continuing.

A memorial fund -- the Gardner Family Children's Memorial Fund -- has been established at Capitol City Bank in Topeka.