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Thursday, August 14, 2008
Updated: August 16, 8:37 PM ET
Exposure to high temperatures could have long-term effects

By Bill Borden
Special to ESPN.com

One of the "hot" topics [sorry, couldn't resist] of late is how hot the interiors of the new Sprint Cup cars get during competition. My first reaction to all the reporting on it was to declare today's drivers to be a bunch of wimps compared with drivers of days gone by, but I uncharacteristically decided to do some research to see if the new car really is hotter than the old ones from the past.

AJ Allmendinger
A.J. Allmendinger's heel cups, which protect a driver's feet from the excessive floor heat during a race, sit in front of his car before a Sprint Cup race.
While I found some things that could indicate the temperatures should be lower for the drivers in the new cars, I found several others that do, in fact, indicate the cars are hotter than their predecessors.

First, let's look at some of the things that should be helping reduce the heat being felt by the drivers:

NASCAR re-routed the exhaust pipes to exit the right side of the new car versus having them exit on the left side directly under the driver's seat in the old car. Exhaust temperatures can climb as high as 1,600 degrees at times so that was like sitting directly on top of an open fire in the old car. Some of the radiant heat they produce was moved away from the driver by designing the pipes to exit on the right side.

Improved blending of materials for fire suits and new Kevlar and/or carbon fiber helmets have made them lighter and safer while helping to reduce driver fatigue, according to John Schneider with IMPACT Racing Products -- a leading manufacturer of driver safety equipment founded by Bill Simpson.

Similarly, dramatic improvements in reflective and insulating materials such as ceramic cloth have helped to cut down on the amount of radiant heat that makes it into the cockpit.

The new Sprint Cup car is not as aerodynamically slick as the previous car so there should be more air finding its way into the cockpit to help cool off the driver during competition.

The cockpit interior of the new car is bigger, which should afford more opportunity for air to circulate around and help cool off the driver during competition.

So, based on the above information, one would assume that the new car should be cooler than the old car. If there weren't other contributing factors then it might be true but NASCAR and the teams have also made other changes that now make the new car hotter.

First and perhaps foremost is the design of the floor pan in the new car. NASCAR, in an effort to make the car safer, narrowed the transmission tunnel so they could move the driver's seat more toward the center of the car and away from the door bars to gain more crunch room. By reducing the size of the tunnel they restricted the airflow that could evacuate from the engine compartment and flow under the car thereby creating more radiant heat under the hood.

Air that used to flow relatively freely out of the engine area via the transmission tunnel now gets trapped in there and raises the radiant temperatures through the firewall and under the car as well.

Another contributing factor is the improved materials now being used for brake pads and rotors that now allow them to operate more effectively at much higher temperatures than before. The gain in performance produces more radiant heat that also gets trapped underneath the engine compartment area.

The air flow under the car has also been drastically reduced with the addition of the splitter on the front end of the new car. The teams are setting up their cars with bump stops that hold the splitter right down to the surface of the track thus preventing much air from going underneath the car. While this has an enhanced aerodynamic value it also contributes to the radiant heat buildup under the car.

The hotter the car gets underneath then the more it radiates heat into the track. And the hotter the track gets then the hotter the underneath of the car gets.

You may recall that earlier this year some teams were having issues with their power steering pumps not operating properly. The added heat under the hood is a contributing factor for those pump failures. Teams are now starting to run coolers on their power steering pumps to reduce the chance of failure. Something they did not have to do with the previous car.

The right side windows of the cars have been closed off for several years now both for aerodynamic and safety reasons. The aerodynamic reason is that the open windows used to trap air inside the car and slowed it down. But the open windows also allowed air to flow more easily to the driver. Closing the windows makes the cars faster but also makes them hotter. The safety reason is that the cars tended to take flight when they turned sideways so closing off the windows reduced the number of unscheduled flights.

Another factor is the foam that NASCAR has added around the bars in the doors to help protect the driver in case of a side impact. This foam both absorbs heat and acts as an insulator to help trap hot air in the car. It was actually catching on fire in early runs of the new car until NASCAR made adjustments for it.

Teams can run NACA ducts in the side windows to help flow air to critical parts of the car but NASCAR will not let them run sucker ducts, which could really aid the drivers by getting fresh air to them. NACA ducts work by scavenging air from the "boundary air" that flows over a car at high speeds. Boundary air is the layer of air that forms between the body of the car and the mass of air flowing by at high speed. A sucker duct works in the opposite manner of a NACA duct and sucks air out of an area -- think venturi vent. NASCAR could alleviate some of the heat problems by allowing more ducting into and out of the cockpit and engine compartments but creative teams would find a way to use it to their aerodynamic advantage and thereby circumvent the rules, so NASCAR will not allow sucker ducts in their cars.

Another major contributing factor for why the drivers are feeling the heat so much in the new car is the fact they are basically enveloped in a cocoonlike seat that protects them from harm but also prevents any air flow circulation around them. If you are claustrophobic then you do not want to sit in the new race seats because they fit you like a glove and you have very little freedom of movement.

Tony Stewart
Tony Stewart looks like he needs to replenish his fluids after this race.
So through improvements in safety and competition we have raised the potential for radiant temperatures to be higher in the new cars and we have reduced the opportunity for any cooling air flow to circulate around the driver. However, some teams choose not to take advantage of all the opportunities they have available to keep their driver cool because of the added weight that is incurred by doing so.

Drivers can also use cool suits and cool helmets and other space-age technology to help them keep cool at some sacrifice in competitiveness. The downside of these advanced cooling systems is that, if they fail, the driver will end up being even hotter because he is encased in a vest that traps even more heat and can become a heater instead of a cooler.

One term I kept coming across in my research for the effects that excessive heat might have on a driver was the term "heat soak." Drivers face temperatures of up to 140 degrees in their cars, which has the potential of doing either short-term or long-term damage to their health.

If their core body temperatures rise to 104 degrees Fahrenheit or 40 degrees Celsius for any prolonged period of time then they will probably experience heat stroke, said Dr. Peter Springer, medical director for emergency services for Volusia County, Fla. Springer has extensive emergency room experience in some of the hotter climes of the country, such as Florida, California and Louisiana and therefore has seen his share of heat exhaustion and heat stroke during his career. He said the short-term treatment is to rapidly cool and hydrate the patient as quickly as possible.

For the most part, heat exhaustion will cause the sufferer to have headaches, muscle cramps or weakness, fatigue and dizziness for the short term. Heat stroke sets in when one's mental state changes and things like one's ability to reason and one's motor sensory skills become diminished. It can lead to delirium, convulsions or seizures and coma, which are not good states to be in if you are driving a race car. That, to me, is becoming a real possibility with today's drivers and therefore should be considered a safety factor when they are competing out on the track where good reflexes and mental acuity are very important. Actually some of the above descriptions of heat exhaustion describe a lot of drivers that I know so there must be something to it.

The U.S. military has done extensive research on the short-term and long-term effects of heat-related illnesses, Springer said. He cited one study done by the Department of Veteran affairs concerning the long-term effects of heat-related illnesses. In that study it states that: "About 15-20 percent of patients with heat stroke may die of the acute illness. While most will recover fully, some 10-15 percent will experience prolonged and/or permanent medical problems including neurological, cognitive and behavioral deficits from small strokes in the brain. Liver abnormalities and heat intolerance are also side effects. Sounds like a lot of fun to me! Makes you wonder if making all those millions is worth the health risks that could plague a driver for the rest of his life.

Anyway, back to the term "heat soak" which refers to your body soaking up heat and not being able to get rid of it through sweating or surface cooling. The body's core soaks up the heat to the point that the organs begin to fail or shut down from the stress of the extreme heat.

My main concern is for these drivers when they get stopped under a red flag condition during a race and then sit there and literally roast in their cars. NASCAR officials bring them bottles of water but that just allows them to partially hydrate their bodies and does very little in helping them to cool down their core temperatures.

You would think that a sport as big as NASCAR [and the teams] would have a better solution for the problem. Some of these guys could be jeopardizing their long-term health without even realizing it. A simple plastic turbo fan that could be activated to blow air on the driver when the car is stopped could prevent potential health problems for them. A turbo fan only weighs a pound or two and could be worth its weight in gold for a suffering driver. After all, he loses 10 pounds or more by sweating during the race, so it would be a fair trade-off.

Some of the old drivers probably could have sweat out up to 20 pounds of beer from their activities the night before a race and not miss a beat but the more fit drivers of today don't have a lot of extra fluid to lose even though they hydrate themselves as much as possible before a race.

OK, OK, Tony Stewart might fit the old mold better than the new one but he is the exception to the rule. At least he quit climbing fences this year. Oh, wait a minute, he hasn't won a race this year has he!

Bill Borden is a former championship winning crew chief who operated David Pearson's Racing School for many years.