Doctors are warning parents that there is never a safe time to leave a child alone in a hot car.

Dr. Ari Perkins, the head of the Emergency Department at Norwalk Hospital, says even leaving a child in a hot car for a few minutes could be fatal.

On a day when it's 90 degrees out, Perkins says the heat inside a car gets concentrated and is too much for small bodies. Children exposed to heat when left alone in a hot car can quickly get hyperthermia or heat stroke, or even die. Cracking windows or not parking in direct sunlight will also not make a car significantly cooler.

Perkins advises parents to have something to remind them to check the backseat when getting out of their car.