• The mother was preparing for her 8-year-old daughter's birthday party
  • The boy remained in the car for two to three hours 
  • It is unclear whether the mother will face charges

Houston, Texas -- A 5-year-old boy died after being left inside a hot car for hours while his mother was making arrangements for a birthday party.

The family was preparing to celebrate the boy's 8-year-old sister's birthday Monday.

The two children had accompanied their mother to a store to buy items for the party. When they returned, the mother and daughter exited the car in a hurry to prepare for the party. The boy, meanwhile, remained in the back of the car and was strapped to his seat, CNN reported.

The child knew how to unbuckle himself and get out of the car. However, the car they used Monday was a rental car and the boy may not have been familiar with the vehicle's door safety lock, investigators said.

"The door did not have any kind of child safety lock enacted or anything like that," Harris County Sheriff Ed Gonzalez told local television station KTRK.

The boy was inside the hot car for about two to three hours until the mother started looking for him. She found him unresponsive and still buckled in his seat.

Officers arrived at the scene after the mother called 911. The boy was pronounced dead.

"This time the child didn't make it out and again with the business of the activities that they were preparing for, it took a while for them to notice that the child wasn't in the house," Gonzalez told the outlet.

The tragic incident occurred as Monday saw record high temperatures in Houston. It is unclear whether the mother will face charges following the death of the boy.

Texas reports the highest number of hot car deaths in the country, according to Amber Rollins from the non-profit Kids and Car Safety.

"Most people don't realize that the majority of the increase in temperature inside of a car happens within the first 10 minutes," Rollins said, adding that a child's body can "heat up 3 to 5 times faster than an adult."

Children should know how to honk a vehicle's horn, turn on flashers and try to open a front door if they can't get out through a back door, Rollins said. Parents should also look in the back of the car before leaving.

Representative image Credit: Pixabay / AutoPhotography