Traveling to new places may introduce you to environments which put new stresses on you physically, from altitude, temperature, humidity, air pollution, new allergens, and so on. This post will discuss the various environmental stressors and how you can minimize their negative impact on your health.
At altitudes over 4000-5000’, many people experience breathlessness and possibly fatigue due to the reduction in oxygen in the air. Above 7500’ some people may experience more severe symptoms known as “altitude sickness” or “acute mountain sickness” (AMS). It’s difficult to know who will get AMS and at what altitudes this will occur as there are no specific health factors that indicate a susceptibility to AMS. Some people just get it quicker than others. Most people can ascend to 7500’ without problems. As people ascend continually higher their risk of developing AMS increases, as does the risk that a person’s AMS can progress to high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE), both life threatening conditions.
General symptoms of AMS include headache (as the primary symptom), combined with one or more of the following: lack of appetite; nausea; vomiting; fatigue or weakness; dizziness or lightheadedness; swelling of hands, feet, or face; insomnia; shortness of breath on exertion; nosebleed; persistent rapid pulse; drowsiness; excessive flatulence; general malaise.
Severe symptoms of AMS, which may indicate life-threatening symptoms of edema (fluid accumulation in body tissues) include: (HAPE symptoms) persistent dry cough, bronchitis-like symptoms, fever, shortness of breath when resting; (HACE symptoms) headache that doesn’t respond to painkillers, unsteady gait, gradual loss of consciousness, increased nausea and vomiting, and retinal hemorrhage.
Descent to lower altitude alleviates the symptoms of HAPE and HACE. Should you or someone in your group start to show symptoms of these more serious conditions, you should get them or yourself to a lower elevation as quickly as possible. If you are alone, get help from someone who can transport you to a lower elevation immediately.
Ascending slowly is the best way to avoid altitude sickness. Travelers who encounter altitude sickness symptoms are often those who fly from low elevations to cities at high elevations, such as La Paz, Bolivia at 11,942’, or Lhasa, Tibet at 11,995’, Quito, Ecuador at 9350’, and Bogota, Colombia at 8660’. If you can fly into a lower elevation city and make your way overland to your high altitude destination, making stops at a couple cities at intermediate elevations along the way, you can acclimatize yourself to the elevation change gradually and experience less problems. Ger and I flew to Leh, India at 11,483’ and experienced headaches the first day and shortness of breath, fatigue, and difficulty sleeping for several days after we arrived. We took the bus when we left. We should have done the reverse and taken the bus up and the plane down. Our daughter, Megan, flew from Santiago, Chile to La Paz, Bolivia and said she didn’t experience much more than some breathlessness and fatigue for a day or so. She is obviously a potential mountain climber. Being at such a high altitude, La Paz is understanding of altitude sickness issues. The hostel where she stayed had an “oxygen room” where guests could strap on an oxygen mask to help with altitude symptoms.
When you arrive at high altitude locations you should avoid strenuous activities and keep hydrated. Avoid alcohol which dehydrates you and is also a respiratory depressant which will slow down your acclimatization. Even though you may experience insomnia, avoid sleeping pills which also depress respiration.
Dehydration and Heat Stroke
Dehydration can occur a couple ways. The first is from excessive sweating as the body tries to cool itself in hot climates. Sweating causes the body to lose both water content and essential body salts, such as sodium, potassium, calcium bicarbonate, and phosphate. Another way dehydration can occur is from diarrhea, vomiting, and fever.
Symptoms of dehydration include: thirst (obviously), less-frequent urination, dry skin, fatigue, lightheadedness, dizziness, confusion, dry mouth and mucous membranes, increased heart rate and breathing. In children, additional symptoms may include: dry mouth and tongue, no tears when crying, no wet diapers for more than 3 hours, sunken abdomen, eyes or cheeks, high fever, listlessness, irritability, skin that doesn’t flatten when pinched and released.
In cases of mild dehydration, rehydration with water or, better yet, sports drinks which replace lost electrolytes and salts, will do the trick. In more serious cases, particularly if the affected person is not able to hold down fluids due to vomiting, medical attention should be sought so that IV fluids may be administered. When I was in my twenties I had a roommate who became dehydrated from vomiting excessively. I ended up taking him to the emergency room at the hospital and he was so dehydrated they said they had difficulty finding a vein to administer the IV.
In hot climates, pay special attention to how much fluids you are taking in. In a temperate climate the average man needs about 16 cups of fluids per day and the average woman needs about 11. We take in about 20% of our fluids each day from food, so this lowers the actual fluid intake requirement to 13 cups for men and 9 cups for women. You should increase these requirements if you are in hot climates or you are exercising. According to OSHA, if you are outside and the temperature is 103-115°F, you should be drinking an extra 4 cups of water every hour. Extended hourly fluid intake should not exceed 6 cups per hour or 12 quarts per day, so if it’s that hot…take a break and get into the shade. When exercising, you should drink 1-2 cups pre-workout and an additional ½ cup every 15-20 minutes. Post-workout you should continue to replace any lost fluids and electrolytes. When you are well hydrated, your urine should be light yellow or colorless.
Allowing yourself to become too dehydrated in hot climates or while exerting yourself can lead to a more serious conditions, such as heat exhaustion and heat stroke.
Heat exhaustion isn’t as serious a threat as heat stroke, but it isn’t something to take lightly. It can occur when you have been exposed to high temperatures accompanied by dehydration. There are two types of heat exhaustion:
- Water depletion. Symptoms include excessive thirst, weakness, headache, and loss of consciousness (fainting).
- Salt depletion. Symptoms include nausea and vomiting, muscle cramps, and dizziness.
Other symptoms of heat exhaustion can include: confusion, dark colored urine, pale skin, profuse sweating, and rapid heartbeat. Treatment for heat exhaustion is pretty much the same as treatment for heat stroke, listed below.
If left untreated, heat exhaustion can progress to heat stroke. In hot countries every year thousands of people die from heat stroke. Heat stroke occurs when the body becomes overheated, with body temperatures greater than 104°F . This happens when the body’s thermoregulation (i.e. sweating to get rid of excess heat) is overwhelmed by a combination of excessive environmental heat, excessive metabolic heat production (from physical exertion), or insufficient or impaired heat loss (high humidity, excessive insulation, etc.). Substances that inhibit cooling and cause dehydration, such as alcohol, diuretics, stimulants, some medications, and age-related physiological changes can further contribute to a the potential for getting heat stroke. In environments which are not only hot but humid, it’s important to realize that high humidity reduces the body’s ability to cool itself by perspiration and evaporation. Heat stroke is more common in people over 50 due to decreased blood circulation, sweat glands which become more inefficient with age, weakness due to age-related illnesses, low sodium diet for high blood pressure, and various medication that older people may take for heart or blood pressure problems. Heat stroke is also more common in people who are overweight or underweight.
The main diagnostic symptom for heat stroke is elevated body temperature, over 104°F . Other symptoms may include the following:
- Throbbing headache
- Dizziness and lightheadedness
- Lack of sweating despite the heat
- Red, hot, and dry skin
- Muscle weakness or cramps
- Nausea and vomiting
- Rapid heartbeat, which may be either strong or weak
- Rapid, shallow breathing
- Behavioral changes such as confusion, disorientation, or staggering
Heat Stroke can best be prevented by taking steps to avoid overheating and dehydration. Staying in the shade, preferably in a location with good air movement, either from a breeze or fan, drink lots of cool fluids, wear light, loose fitting clothing (or very little clothing) which will allow perspiration to evaporate and cool the body. If you must be in the sun, wear a light colored wide brimmed vented sun hat to keep the head and shoulders cooler, sweatbands wetted with cool water, and avoid strenuous exercise. Avoid drinking beverages containing alcohol or caffeine. If you have taken these measure and are still feeling overwhelmed with the heat and starting to experience any of the symptoms mentioned above, try to get to a place with air conditioning or take cold showers or soak in a bath filled with cold water. Thirst is not a reliable sign that you need fluids. Dark yellow urine is a better indicator of dehydration.
Treatment of heat stroke involves rapid cooling along with standard resuscitation measures. The body temperature must be lowered quickly. The person should be moved to a cool area (indoors, or at least in the shade) and clothing removed to promote heat loss). The person should be sponged or sprayed or bathed in cold water (even iced, if available). Avoid wrapping the body in wet towels or clothes as these can act as insulation and increase body temperature. Cold compresses to the torso, head, neck, and groin will help cool the victim. A fan or air-conditioner may be used to aid in evaporation of the water.
Immersing a person into a tub of cold water is a widely recognized method of cooling. This method may require the effort of several people and the person should be monitored carefully during the treatment process. Immersion should be avoided for an unconscious person, but if there is no alternative, the person’s head must be held above water.
Hydration is important in cooling the person. In mild cases of dehydration, this can be achieved by drinking water, or commercial sports drinks may be used as a substitute. In exercise- or heat-induced dehydration, electrolyte imbalance can result, and can be worsened by excess consumption of water. Low blood salt can be corrected by intake of sports drinks. Absorption is rapid and complete in most people but if the person is confused, unconscious, or unable to tolerate oral fluid, then an intravenous drip may be necessary for rehydration and electrolyte replacement.
The person’s condition should be reassessed and stabilized by trained medical personnel. The person’s heart rate and breathing should be monitored, and CPR may be necessary if the person goes into cardiac arrest.
Air quality in larger cities in many countries is poor due to excessive air pollution from motor vehicles and other sources. WHO estimates that every year 7 million people die prematurely due to the effects of air pollution. In 2013 air pollution was estimated to kill 500,000 people in China each year. Annual European deaths caused by air pollution are estimated at 430,000, an average reduction in life expectancy for all citizens of almost nine months. In 2013, WHO reported that 80% of all urban areas have air pollution levels above what’s considered healthy. For cities with more than 100,000 people in low- and middle-income countries the report found that 98% of those areas had unhealthy air. Don’t underestimate the negative health effects of air pollution.
Persons who are at greater risk for health problems from air pollution are young children, the elderly, overweight people, or people with existing heart or lung conditions, diabetes, asthma, or allergies.
The most harmful pollutants are particulates, especially particles smaller than 2.5 microns in diameter, referred to as “PM 2.5”. PM 2.5 levels start to be a major health problem at level above 35 μg/m3 of air, although WHO recommends keeping yearly average PM 2.5 levels of 10 μg/m3 . Even if we double the “safer” level, most of the major cities in middle- and low-income countries we will be visiting as budget travelers exceed these levels, some by huge margins. In some countries, such as India and China there are dozens of cities with PM2.5 levels in the danger zone. But particulates aren’t the only harmful pollutants in the air. Lately there has been a focus on ground-level ozone and it’s harmful health effects. In addition, there are carbon monoxide, sulphur dioxide, nitrogen oxides, mercury, polycyclic aromatic hydrocarbons, benzene, and dioxins and furans to worry about. There are many resources online where you can go to research the air pollution levels in the cities and countries you are planning on visiting.
About the only thing you can do to deal with air pollution is avoid places where it’s bad. Sometimes if you visit at certain times of the year the air pollution will be lower due to climatic conditions. Most people assume that the hot summer months are the worst time for air pollution, but that’s not usually true. Often the winter months, when locals are burning coal or wood for heat, can be worse. This also varies by type of pollutants. Ozone is usually worst when sunlight is the most intense.
I am sensitive to air pollution and so I try to limit my stays in cities where I know the air pollution levels are higher and get away to places with cleaner air.
If you already have medical issues that are exacerbated by altitude, air pollution only adds to these problems by irritating your lung and further reducing your ability to use oxygen. Be careful and check out your destinations to determine if the health risk is too great for your condition.