The heat inside a parked car can reach dangerously high levels, often exceeding 120°F (49°C) within 30 minutes on a sunny day, and can climb to 150°F (65°C) or higher in extreme conditions. This rapid increase is due to the greenhouse effect, where solar radiation enters through windows and gets trapped, heating the interior faster than the ambient temperature. For example, on an 80°F day, the temperature inside can rise by over 40°F in an hour, posing serious health risks such as heatstroke, especially for children and pets.
The process is accelerated by factors like dark interior colors, lack of ventilation, and direct sunlight. According to studies from the National Highway Traffic Safety Administration (NHTSA), even on mild days, car interiors can become lethal quickly. It's crucial to never leave anyone or anything vulnerable in a parked car, and using sunshades or cracking windows slightly can mitigate some heat buildup.
Below is a table based on authoritative data from NHTSA and AAA, showing how interior temperature rises over time on an 80°F day:
| Time Elapsed (minutes) | Interior Temperature (°F) | Temperature Increase (°F) |
|---|
| 0 | 80 | 0 |
| 5 | 91 | 11 |
| 10 | 99 | 19 |
| 15 | 104 | 24 |
| 20 | 109 | 29 |
| 25 | 112 | 32 |
| 30 | 114 | 34 |
| 40 | 118 | 38 |
| 50 | 121 | 41 |
| 60 | 123 | 43 |
This data highlights the importance of taking precautions, as temperatures can surpass 100°F in just 10 minutes. Always check your car's interior before locking it, and consider remote start systems to pre-cool the cabin safely.
