Years ago, I attended a seminar given by Papa Bear Whitmore, a noted authority on wilderness survival. He made an important observation based on his years of experience surviving the wilderness, teaching wilderness survival and looking for people lost in the wilderness.
He said that when the weather is cold, say 20 or 30 degrees Fahrenheit, people know it is cold, and they prepare for it appropriately. It is when people don't think of the weather as cold that there is a higher risk for problems.
It seems problems are more likely to occur when the temperature is in the 40 to 50 degree Fahrenheit range because people are unprepared for a stop in activity or a sudden weather change. An approaching storm that makes conditions wet and/or windy can cause big problems, beginning with wind chill.
Wind chill can make bearable air temperatures very uncomfortable at the least, and depending on the combination of weather conditions and the athlete's condition, the situation can become downright dangerous.
For example, a 40 degrees Fahrenheit ambient temperature changes to 33 degrees Fahrenheit on your skin with 10 mph wind. Add a cycling speed of 20 mph to that headwind and the wind chill takes the temperature to a frigid 28 degrees.
Wind chill is only part of the equation, and you don't have to be moving at 20 mph to have trouble. Lawrence Armstrong, author of Performing in Extreme Environments, notes a personal experience with cold temperatures in his book. He, along with many other competitors, began a Boston marathon running race in only a T-shirt, shorts and socks because the conditions when the race began were sunny and warm.
As the race progressed, the clouds and wind moved in, causing ambient temperatures to drop. He experienced hyperventilation by mid-race as his body lost heat due to radiation, convection and evaporation. In the final miles, he experienced shivering, muscle spasms and incoordination because his exercise intensity and metabolic heat production had decreased.
You don't have to succumb to cold stress, or an indoor trainer for three solid months, as winter continues to present challenges. It is possible to continue to cycle outdoors when winter envelops your favorite route as long as you know some safety tricks. You should also be able to recognize the early signs of trouble so that exposure to the cold does not become dangerous.
Symptoms of Cold Stress, Hypothermia
There is some disagreement among experts about the number of stages of hypothermia and what body temperature range dictates which stage. The most important things to know are the warning signs.
One of the first warning signs is the body shivers to exercise muscles and produce heat as core temperature drops from around 98.6 to 96 degrees Fahrenheit. A two-degree drop from what is normal for you will probably produce shivering. If you are shivering, it is your first signal that you're heading for trouble. Do not take chattering teeth and shivering lightly.
When body temperature drops to between 91 and 95 degrees Fahrenheit, from 98.6, shivering becomes violent, speech is difficult, thinking is slow and amnesia may occur. Additional symptoms include skin turning to a grayish color, irritability or behavior that becomes combative, drowsiness and an inability to stand and move after resting.
Hopefully you will never experience more than the shivering: the first-warning sign of hypothermia. Keeping yourself warm and dry are two ways you can prevent hypothermia stress.
Tricks to Stay Warm and Dry
One trick to help you stay warm is to fill a Camelback hydration system with warm energy drink. A favorite is apple flavor, since it is similar to hot apple cider. The warm fluid on your back--and eventually in your stomach--helps keep your body temperature up.