by Jim Kerr

Summer’s sun feels wonderful. The grass turns green, the flowers bloom, and trees change the landscape as their leaves unfurl. It all sounds wonderful, but not for your car.

While outside, the temperatures are warm and comfortable, but inside your automobile the temperatures are high enough to fry eggs. Not only is this damaging to the interior, it can be fatal to any living creature. In an unprecedented study funded by GM of Canada and conducted by hyperthermia researchers at McMaster University in Hamilton, Ontario, a research team led by internationally-known Dr. Oded Bar-Or, a pediatrician and director of the Children’s Exercise and Nutrition Centre at the university, gathered data on interior vehicle temperatures.

While everybody is affected by extreme heat, infants and small children are affected more quickly and dramatically than adults. Because of their smaller size, their core temperature can increase three to five times faster than that of an adult.

Heatstroke, or hyperthermia, occurs when the body’s core (rectal) temperature reaches 40.5 degrees Celsius (105 degrees Fahrenheit). Dr. Bar-Or’s research revealed that the air temperature in a previously air-conditioned small car exposed to the sun on a 35-degree C. (95 degrees F.) day exceeds 50 degrees Celsius (122 degrees F.) within 20 minutes and 65.5 degrees Celsius (150 degrees F.) within 40 minutes.

Twenty minutes isn’t very long; less time than it sometimes takes to pop into the corner store and pick up a couple groceries. Leaving a window slightly opened, or “cracked,” on a sunny day may do little to prevent the temperature inside a vehicle from rising to dangerous levels for children, vulnerable adults and pets. Even with all the windows open, the greenhouse effect through the stationary windows can make interior temperatures very uncomfortable at the least.

Most of us recognize the danger of leaving children or pets in a closed vehicle on a sunny day, but very few realize how quickly the temperature rise to dangerous levels. How many times have you walked by a vehicle in the parking lot on a warm day and seen a child or animal inside a closed vehicle?

Now that we know how fast hyperthermia affects a person or animal, lets look at what the sun does to your vehicle. Inside, the closed passenger compartment is an oven cooking the life out of your vehicle. Rubber and vinyl parts start to “gas”. The oils and solvents inside the material evaporate and the parts dry out. You have probably noticed a thin film develops on the inside of the windows after the vehicle sits in the hot sun. This is the residue from baked rubber and vinyl parts.

Cloth interiors also deteriorate in the sun. Materials fade and foam rubber inside the seats starts to break down. Automotive electronics exist remarkably well in a hostile environment, but constant high temperatures can cause failures. One often-overlooked area that is damaged by high heat are the lubricants on all interior moving parts. Everything from climate controls to the brake pedal to seat mechanisms use lubricants to make the parts move smoothly. High heat can dry out these lubricants or even melt them, causing the parts to bind or stick.

So how do we protect the interior from summer’s heat? The best way is to keep it out of the sun. A garage, sunport, or other covered shelter will protect your investment the best. Some car covers have aluminized layers that reflect a lot of the sun’s heat. These work very well, but are inconvenient to put on and should never be installed on a wet or dirty automobile. Dirt between the cover and the vehicle can quickly damage paint on a windy day.

Sunshades, the fold-out cardboard ones you often see inside windshields with the colourful pictures or giant sunglasses, work to reduce interior temperatures. Some even come with sun-reflecting material on them. These are economical, quick to install when parked, and just as quick to remove. Consider one for the back window as well.

Finally, there are lots of chemical protectants designed for dashboards and other vinyl and rubber parts. Spray the protectant on, let it soak for a few minutes, and wipe it off. This restores the flexibility and durability of the parts, but be careful not to get it on electronic controls or they may be damaged.

Park in the shade whenever possible and take care to protect both your vehicle and its occupants. These are common sense for summertime driving. Now, its time to enjoy the warm weather.

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