Planning for significant temperature changes is important when adventuring outdoors. Spring in Northern Nevada brings warm days and cold nights. As a human, our internal chemical processes require a specific temperature range. Therefore, the human body registers external changes in the environment as it works to maintain a constant internal body temperature. When it is unable to adjust for changing environmental conditions and strays out of this range, we can find ourselves in trouble.
The climate in the Great Basin is classified as arid or semi-arid, meaning high temperatures with low precipitation. Because of the low humidity in Nevada, the sun quickly heats the air during the day and without humidity the heat dissipates easily and air cools quickly at night. Thus, resulting in our vast temperature swings. The humidity is also important because it influences how the temperature actually feels. For example, if the air temperature is 85 degrees Fahrenheit and there is zero percent humidity, the temperature will feel like 78 degrees Fahrenheit. However, if there is 80 percent humidity, it will feel like 97 degrees Fahrenheit. Increased air humidity hinders the body’s ability to cool itself, so it feels hotter. This calculation combining the temperature and humidity is known as the Heat Index, and the National Oceanic and Atmospheric Administration provides tables for quick reference ( ).
Regardless of how a person feels the temperature, the human body uses two involuntary processes to regulate body temperature when it is threatening to dip or rise out of the safe zone. Shivering signals that a body is getting too cold and sweating signals that a body is getting too hot. Shivering is a series of muscle spasms. Forcing your muscles to work demands more energy from cells and therefore produces heat. Sweating works through the process of evaporation. Water off the skin’s surface evaporates, just like your swamp cooler blowing warm air over cool water to cool the air in your house. These simple and involuntary actions are important clues to pay attention to as they indicate that your body is working to regulate internal body temperature.
According to the Cleveland Clinic while the human body is generally between 97.7 and 99.5 degrees Fahrenheit, environmental temperatures over 90 degrees Fahrenheit can be dangerous. This is because the body is its own heat source (metabolism) plus the addition of the environmental heat can push a human out of the safe zone. Without proper hydration and cooling periods you may begin to experience heat cramps and exhaustion. If signs of heat exhaustion (faint or dizzy, cool and clammy skin, excessive sweating, and muscle cramps) are not heeded they can quickly escalate into heat stroke (faint or dizzy, hot dry skin, no sweating, and rapid pulse), which is a life-threatening condition.
When shivering begins, hypothermia is the concern. Hypothermia is a dangerous drop in core temperature and can occur in a variety of circumstances but is usually exacerbated by moisture, from falling in a creek to damp clothes from sweating earlier in the day. Dehydration and alcohol consumption also influence hypothermia. Common symptoms of hypothermia, after shivering, are slurred speech, becoming uncoordinated, and poor decision-making skills. Like heat stroke, hypothermia is a life-threatening condition.
The easiest solution to being prepared in the Great Basin is layers. Layering clothing, or having the option to layer, is critical for survival. Utilization of different fabrics is a wonderful perk to living in the 21st Century. Fabrics like wool and synthetics can keep you warm even if they get wet and cotton will actually help you cool by facilitating evaporation when sweating. But, you must have them with you to utilize them, so don’t be afraid to pack more than you may expect to need. Be aware, and adjust your layers throughout the day, to minimize sweating. Damp clothes, even from sweat, get very cold when the sun goes down. Layers for feet are also important; extra socks or dry socks can be the difference between finishing your adventure comfortable or miserable.
Get outside and explore nature! Enjoy the dynamic conditions of spring in the mountains and on your local streets. It is wise to always bring an extra layer, and remember to watch for sweating and shivering as clues for what you need to do to survive.