Leaving young children and pets unattended inside a vehicle, even on relatively mild days, can be very dangerous, even fatal.
Outside air temperatures as low as 23ºC/73ºF can climb to more than 50ºC/122ºF inside a vehicle. Imagine how hot it could get during an actual heat wave. Every spring and summer there are reports of babies, toddlers and pets dying after being left unattended inside vehicles.
Extreme heat affects young children more quickly and dramatically because of their smaller size. Young children have a reduced ability to regulate their body temperature in comparison to adults, which leaves them vulnerable to heat stroke. Heat stroke occurs when our core temperature reaches 40ºC/104º F and can be fatal.
In a small, closed environment, our bodies, especially small or frail ones, can go into shock very quickly causing circulation to vital organs to fail.