The summertime is a popular time for most people to see some of the natural wonders. Unfortunately, many of these places are located in remote areas that experience intense heat.
Three main factors affect hikers in hot environments: temperature, humidity, and direct solar radiation. In response, the human body uses several mechanisms to stay comfortable in hot conditions.
The human body attempts to maintain a core body temperature between 36.5 and 37.5°C. Maintaining the temperature within this range is essential for the proper bodily function of human organs. Heat is produced in the body by normal metabolism, exercise, and shivering. When your muscles contract while you are hiking, they generate heat. When heat must be dispersed, the cardiovascular system stimulates more blood flow to the skin (causing a red or flushed look when exercising hard) and less blood flow to abdominal organs by increasing the heart rate and cardiac output. Respirations increase and result in evaporative cooling from the lungs.
As the outside temperature increases, getting closer to your body’s core temperature, this method of getting rid of extra heat is less effective. Another physiological response is sweating. In dry environments, your sweat evaporates, cooling the surface of the skin. However, in climates with high humidity, sweat does not evaporate, leaving you feeling hot and damp.
Many hikers don’t know all the things to take into account when hiking in a hot summer. Hiking safety isn’t one of the first things that people think of when they go on a hike, but it should be their priority.
Main rules for safe summer hiking
Rule 1: Stay hydrated
Ambient temperature, elevation, exercise intensity, and duration increase the physiological strain, calorie and water demands on your body. This makes summer hiking more difficult than traveling the same distance in cooler temperatures.
Fluid/electrolyte loss can reach up to 1.5-2 liters per hour if you hike uphill in direct sunlight and during the hottest time of the day. When you hike in a place where the air is hot and dry, sweat evaporates instantly, making its loss almost imperceptible.
Dehydration causes blood vessels in the skin to constrict and limit sweat production. Waiting to feel significantly thirsty is a poor strategy since thirst is indicative of early dehydration. On the other hand, episodes of exercise-associated hyponatremia (EAH) have occurred because people forced themselves to drink unnecessarily to meet a fluid goal. Fluids should be cool beverages containing a maximum of 6% carbohydrates. A higher concentration of sugar delays gastric emptying, and when the solution is cool, the body absorbs it more easily. Salt can be replaced through fluids or dietary intake.
Even a mild level of dehydration can turn the joy of hiking into an unpleasant experience. The more dehydrated you become, the less efficient your body is at self-cooling. This puts you at greater risk for heat-related illness. Over-hydration and lack of salty foods can also be very dangerous, as this may lead to a condition called hyponatremia.
Hyponatremia usually occurs for individuals in a high heat environment who have overhydrated with water while not also eating. Avoiding overhydration is the primary strategy to prevent EAH. Eating and drinking moderately throughout the day and using rehydration tabs or mixesÊare good methods to prevent hyponatremia while providing the body with the needed nutrients to fuel a day of hiking.
Avoid consuming plain water and encourage consumption of salty foods as long as there is no neurological deficit or risk of aspiration. A treatment paradox is that EAH and dehydration may present similarly, but require opposite treatment: hydration for dehydration but fluid restriction for EAH.
When homeostasis is not maintained, mild to fatal heat illness can occur. Assessing the environment for heat illness risks is essential for successful hiking in hot environments.
Rule 2: Choose appropriate clothing
Your choice of clothing for hiking in hot weather will depend on the region of the country and the time of year. You need to choose very carefully your hiking outfit before you set off for a hike in hot weather because hiking in the heat will increase perspiration.
In very hot weather, choose lightweight, loose-fitting, light-colored long-sleeved clothing for ventilation and heat reflection. The material should be breathable and have water-wicking properties that aid in evaporative cooling. Wear synthetic clothing that will wick the sweat from your body and dry quickly. You should also consider what accessories you are wearing as well. Wear sunscreen and a hat if you are out in the sun in a place where there is little tree cover as they will provide proper protection against potentially harmful UV rays. A bandana around the neck can be helpful too.
Your first inclination may be to wear shorts and a short-sleeve shirt, and in many places, this may indeed be excellent. Many hikers prefer to wear convertible pants with legs that zip off to become shorts. You can read our post about the pros and cons of convertible pants and shorts here.
While tempting, cotton T-shirts are not recommended for backpacking (except in desert climes) because they get soaked with sweat and chafe your skin. For greater comfort, select a loose-fitting T-shirt made from polyester. It offers good airflow and fast drying while protecting your shoulders from the sun.
In areas where ticks, mosquitoes, and black flies are a problem, your best option is to wear long clothing, tuck your pants into your socks, wear light colors so you can see ticks more easily, and even wear a head net if the bugs are really bad. You might also consider treating your hiking clothes with permethrin.
Rule 3: Cover up
Clothing and shade are behavioral actions that complement the bodyÕs internal heat regulation mechanisms, but environmental variables such as air temperature, humidity, wind velocity, and radiation have the greatest impact on heat exchange.
Ultraviolet radiation can cause common sunburn. The energy in solar radiation encompasses wavelengths measured in nanometers (nm). Ultraviolet radiation (UVR) is divided into UVA, UVB, and UVC, with wavelengths of 315 to 400 nm, 280 to 315 nm, and 100 to 280 nm, respectively. UVA and UVB rays are of the most concern, as UVC is mostly absorbed by the ozone in the Earth’s atmosphere. Sixty-five percent of UVR reaches the Earth’s surface in the middle of the day, between 10 am and 2 pm.
Sunburn is easier to prevent than treat. Limiting the chance of burning involves avoiding excessive UVR, especially exposure between 10 am and 4 pm, covering up with tightly woven clothing, wearing a wide-brimmed hat, wearing sunglasses, seeking shade, and using proper sunscreen with frequent applications. Dark-colored fabrics are more protective than lighter or white fabric.
Sunburn is the result of excessive UVR exposure, which can be mild to severe. Mild sunburn consists of local heat, red skin, and pain. Severe sunburn may include swelling, itchiness, blister formation, malaise, weakness, fatigue, nausea, chills, fever, and headache.
Once a sunburn has developed there are no effective treatments, only measures that can reduce the discomfort. Medications for pain and decreasing inflammation can help, along with cooling the area with a damp cloth or cold compresses. Alternatives such as aloe vera, oatmeal, or baking soda are anecdotal and may provide some relief but have not been scientifically proven. Medical attention may be required for severe sunburns.
Rule 4: Avoid midday hiking
Even if you wear convertible pants that can easily turn into shorts, avoid hiking in the hottest part of the day (mid-afternoon), go at a slow pace, rest frequently, and take sips of water every 15 minutes or so.
If you want to have a safe and enjoyable hiking trip, you need good timing to avoid the heat. You need to be very careful and limit your exposure to the direct sunlight. Hike in cooler weather – early in the morning, late in the afternoon, in the evening, and at night.
Plan your day so you are not hiking between the hours of 10 am and 4 pm. A great way to avoid the heat is to start walking early. It’s cooler in the mornings and the temperature will be more comfortable to hike in. Late afternoons and evenings are also more suitable for summer hiking. Always bring a flashlight or a headlamp to give yourself the option of hiking out after dark if something slows you down or you choose to continue walking after dusk.
Rule 5: Cool regularly and rest
Taking regular breaks will help to ensure you don’t become dehydrated. Give your body enough time to recover without wasting your energy in the heat. Try to find a shaded area to get out of the sun. Remembering to stop and take a break allows you to enjoy the experience of being out on the trails much more.
Active cooling methods should be administered. Whenever you reach near water, keep yourself wet. This will not only cool yourself but also make a wonderful difference in how well you feel, especially at the end of the day. Eventually, it will help decrease your core body temperature. Additionally, dip your bandana in water when you are really hot and it can make you feel cooler. If you are wearing a hat also dip it in water periodically.
The inability to stay cool and hydrated may be fatal while hiking in hot temperatures. To prevent dehydration, heat stress, sunstroke, and sunburn, you must be able to keep yourself cool, hydrated, and sun-screened or skin-covered. Wear appropriate and breathable outfit, including shorts or convertible pants (or regular hiking trousers), loose-fitting and light-colored hiking shirt or T-shirt, wool/synthetic socks, hat, and bandana. Don’t forget your sunglasses too.
Start your hike early in the morning and avoid midday hiking. Take a break near shade and water to avoid the worst heat of the day. Have plenty of rest and cool regularly.
If you follow these five rules, your summer hiking trips will be safer and more enjoyable.