A father whose child died from heatstroke after being left in a hot car is warning parents not to make the same mistake.

Reginald McKinnon said he discovered his daughter was dead at the end of his workday when he realized he forgot to drop her off at day care.

"It's been over four years and we still deal with it," said McKinnon. "My family and my daughters -- now I have to take care of."

During a demonstration at the Children’s Services Council authorities said a small child's body heats up three to five times quicker than an adult's does, and even a car parked in the shade can reach lethal temperatures.

"The temperature still rises 20 degrees for every 10 minutes," said Capt. Albert Borroto of Palm Beach County Fire Rescue. "So even running into the store to get a gallon of milk -- that temperature in the shade can reach over 100 degrees."

And authorities said a 107-degree body temperature is deadly.

"If you see something, say something," said Capt. Frank Kitzerow of the Jupiter Police Department. "Call 911. Don't go looking for the parent, because your call could save someone's life."