Stay safe in the heat! Limit outdoor activities. Drink plenty of water and avoid alcohol. Wear light-colored clothing and sunscreen. Work outdoors early or very late in the day.
Also, NEVER leave children, disabled or elderly adults, or pets in parked vehicles. Studies have shown that the temperature inside a parked vehicle can rapidly rise to a dangerous level for children, pets, and even adults. Leaving the windows slightly open does not significantly decrease the heating rate.
Original source can be found here.