Sitting inside a locked car with no air conditioning can become dangerous relatively quickly, especially in warm or hot weather. The interior of a car can heat up rapidly, even with the windows cracked open, due to the greenhouse effect. The greenhouse effect occurs because the sunlight entering the car is absorbed by the interior surfaces, and the resulting heat is trapped inside, leading to a temperature increase.
The exact time it takes for a locked car to become dangerously hot depends on several factors, such as the outside temperature, humidity level, and the color of the car's interior and exterior. However, as a general guideline, here's what you can expect:
Within Minutes: On a hot day, temperatures inside a locked car can rise rapidly. Within just a few minutes, the temperature inside the car can become significantly higher than the outside temperature.
Within 10 Minutes: Even on a moderate day (around 80°F or 27°C), the temperature inside a locked car can reach around 20-30 degrees Fahrenheit (11-17 degrees Celsius) higher than the outside temperature within 10 minutes.
Within 30 Minutes: On a hot day (around 95°F or 35°C), the interior temperature of a locked car can reach dangerous levels within 30 minutes, sometimes exceeding 120°F (49°C) or more.
The extreme temperatures inside a locked car can lead to heat-related illnesses, such as heatstroke and dehydration, which can be life-threatening. Children, elderly individuals, and pets are particularly vulnerable to heat-related injuries in such conditions.
It is crucial to avoid leaving anyone, especially young children, elderly individuals, or pets, unattended inside a locked car without air conditioning. Even on mild days, the temperature inside a car can increase to dangerous levels quickly. If you encounter a situation where you must wait in a parked car, ensure the air conditioning is on, or keep the windows cracked open for proper ventilation. If you notice someone in distress inside a locked car, take immediate action to help them, such as by calling emergency services.