TRAVELING IN THE HEAT

Travelling in hot and muggy cities that are blanketed in smog is no only uncomfortable; it can be outright dangerous to persons suffering from respiratory diseases, heart trouble and generally anyone over 50 years of age.

Undoubtedly,  smog  is  a  terrible  factor  to  deal  with since it is a killer. For example, in London, England, during four days in December 1952, as many as 4000 people died from high concentrations of photochemical smog that smothered the city.

As most of us know, the tailpipes of our automobiles emit gaseous  contaminants such as  nitrogen  oxide,  carbon monoxide,  sulfur  dioxide  and  hydrocarbons  in  the  form  of unburned gasoline. The nitrogen oxides which are turned into nitrogen dioxide and hydrocarbons are at their worst during the days when they are changed  by  sunlight  into  substances scientists call peroxyacetyl nitrate.  Ozone occurs naturally in the upper atmosphere and protects the earth from the harmful rays  of  the  sun, but  when  it  is  produced  in  the  lower  atmosphere  as  a  result  of  the photochemical reactions that occur when the emissions from the exhaust pipes are exposed to sunlight, its effect can create serious pulmonary difficulties.

Nitrogen dioxide and sulfur dioxide are both used in the manufacture of sulfuric acid and combined with humid air, these gases are converted into minute particles of sulfuric acid that emits from the thousands of exhausts of motor vehicles onto the streets of a city like New York. When inhaled, the acid-like sulfur dioxide gas lodges in the walls of the linings of the lungs and impede the intake of oxygen and can scar the alveoli--the minute air sacs of the lungs. Once scarred, they do not have the elasicity to keep stretching. If this form of pollution can erode the statues of Europe until they become rounded like Henry Moore's masterpieces, how then can the delicate tissues of the lungs of human beings fare better?

Carbon monoxide is created by the incomplete burning of gasoline or any other like fuel and is both colorless and odorless and  deadly.  It competes with the oxygen for a place in the blood cells and its  presence  in  the  blood  prevents  sufficient  oxygen  from reaching the tissues  which  can  result  in  death.  Concentrations of carbon monoxide in the open air are usually below  the  levels  that  are  dangerous  but  under  stagnant atmospheric conditions in heavily congested areas such as New York  City,  the  concentrations  are  heavy  enough  to  cause dizziness, headaches and loss of alertness.

If you combine the tailpipe emissions with the other contaminants that pollute the air--such as what comes from smokestacks of factories, and then add the contaminants that are inhaled by cigarette smokers, it is enough to hasten an unhealthy person to his grave.

Heat prostration is undoubtedly one of the biggest killers of seniors who travel in areas where the air temperature is very warm. It affects every part of the body.

The human body's temperature is between 98 and 100 degrees Fahrenheit with the normal readings being at 98.6 degrees (37º Celsius) When the body temperature goes above 100 degrees, a person begins feeling uncomfortable.

The chief source of body heat is not the sun's rays or radiated heat from a fire which strikes the skin, but rather our internal organs such as the heart, liver and kidneys. An average person's diet releases in one day enough heat to incinerate a pound of coal into ashes.

The basic metabolism of a person at rest produces about1,700 calories of heat per day for men and 1,500 for women. This is sufficient heat (assuming that there is no loss) to raise the temperature by nearly one decree Celsius (2 degrees F) per hour. Extreme activity, such as jogging in hot, humid weather can  increase  the caloric  level  as  high  as  6000,  thereby increasing the body temperature by over 3 degrees Celsius (6º ) Fahrenheit) per hour.

It must be remembered that in any muscular activity, only 25 percent of the energy produced is converted into work, the remaining 75 percent is converted into body heat. Another thing to remember is that the hypothalamus in the  brain regulates body temperature and in the very young and with older people, it operates less efficiently.

Heat is easily absorbed by water, and the bloodstream which is 80 percent water, is continually passing through the hot central regions of our bodies on its way to its surface. If it didn't, we would literally burn to death. It only takes 40 seconds or so for the hot blood to leave the region of our steamy hot internal organs to flow to the slender vessels that are tucked less than 1/20 inch from the surrounding air. Since our skin is adjacent  to  the  outside  world,  outside  air  temperature  is important as a means of regulating body heat. About 70 percent of the body's excess heat gets carried away in this way (2.1 litres-- three and a half pints); Another 15 percent is removed by sweating (.45 litres-- less than a pint);  and  by  just  breathing  alone,  we  lose  10 percent  by  evaporation  from  the  lungs  (.30 litre);  and  the remainder is lost in urine and feces (1.5 litres--two and a half  pints)  People who suffer from attacks of diarrhea during their travels can lose a great deal more water from their bodies. 

If a person loses 1 percent of his body weight in fluids, he receives his first warning—he gets thirsty. If he loses as up to 5 percent of his body weight in fluids, he will be in a state of collapse. For example, when a person walks through the streets of a city on a hot humid day, and his body heat goes up, he feels giddy and tired. This effect is called heat syncope. The traveller experiences  sudden  dizziness, headache, weakness, and fainting. His skin becomes hot and dry, and his heart begins to beat rapidly and he suffers from muscle cramps.

But the other symptom of heat syncope, tiredness, is not so compelling and is one that weary travellers try to fight. They shouldn't.  When their bodies begin to get seriously overheated, they should try to get into an air conditioned building and sit down if at all possible. If such a person doesn't seek this kind of relief, he may suffer from heat prostration.

And if he loses 10 percent, his temperature will rise to 105 degrees fahrenheit (40.5 C) and convulsions will begin and soon thereafter, delirium. In this malaise, the usual ways of regulating the heat in the body goes berserk, just at the time when they are most needed. The body actually starts breaking down more foods, thus producing more heat. Then the most efficient cooling mechanism, sweating, totally stops. Heat builds up inside the body and with no sweating to bring relief, and with no re-routing of internal blood to the surface, the skin acts like a close-fitting plastic bag.  Inside  that  enclosure, the  body  temperature  rapidly  increases  beyond  105  degrees Fahrenheit.

A loss of 15 percent will increase the body temperature to 107 degrees Fahrenheit (41.6 C) and bring the victim into a state of unconsciousness. At this point, he is beyond self-help.

A loss of 20 percent will increase the body temperature to 111 degrees Fahrenheit (43.8 C). At this temperature, the body is overloaded. All chemical reactions are taking place at about twice the rate at usual resting temperatures. Millions of nerve cells  are  firing  for  no  reason  at  all,  massive  amounts  of proteins  are  being  broken  down  and  circulated  under  high pressure. Brain cells begin to unravel. Steam rises in small amounts from the eyeballs and body tissues literally melt out of shape. Invariably death follows. 

Many  travellers  who  have  sought  relief  from  the overheating of their bodies by turning on their electric fans in their hot and stuffy non-air-conditioned rooms have died in their chairs after they fell asleep because they were unable to replace the 20 percent loss of water that gradually escaped from their bodies during the evaporation process.

It is necessary for the average person in  normal temperatures to ingest at least 2 liters of fluid  each day—be it water, soft drinks, fruit juices or fresh fruit. But in hot weather, the ingestion of fluid must be greater. In the tropics, sweat loss can be as high as 2 litres (31/2 pints) in an hour. If a man weighing 70 kgs (156 lbs) loses 2 litres of water every hour while in the tropics and doesn't replace that loss, he will die within three hours.

Whenever the brain decides that the body is hotter than is good for it, it sends signals to over two million holes scattered across the skin. The brain's nerve signals cause tiny muscles to squeeze down on even tinier rolled-up tubes that conveniently form  in  the  bottom  of  these  holes,  and  which,  even  more conveniently, have a few drops of a mostly watery fluid waiting in them. Each tube is so tightly coiled that if it were unravelled it would stretch as much as four feet. The squeezed water rushes up in a gush--as two million miniature geysers.  Each sweat gland fires on its own separate schedule, having only enough fluid stored inside to erupt once every nine seconds. It should be as no surprise to anyone that the reservoirs of water left in our bodies get seriously depleted as we sweat.

Half of our sweat comes out on our chests and backs, a quarter from our feet and legs and the remaining quarter from our heads, arms and hands.  For some strange unknown reason, more comes from the front surfaces than the back and it is first noticeable on our foreheads, neck, chest or the top of our lips.

Once any sweat reaches the surface of our skin, it's ready to be evaporated away by the gentlest breeze.  The evaporating water takes heat away from the skin thereby cooling the skin as it goes. That's why standing in front of a fan on a hot day feels refreshing to some degree.

However, our sweat is not simply water. It also contains salt, potasium metal, (the seventh most common element in our bodies) milk sugars and as an added treat, a substance called, bradykinin. It, incidentally is the main component of a wasp sting. It is what opens our arteries, thereby making it possible for more of our hot blood to reach the area just beneath the surface of our skin. Since our skin (which is also an organ and if peeled from our bodies, would cover a kitchen table) contains a third of the fresh hot blood from our hearts, it follows that a little cooling on the  surface  of  our  skin  can  do  a  lot  to  keeping  our  body temperature down to its normal level.

Low humidity in the air makes it possible for our sweat to evaporate in the air, thereby releasing more than the usual 15 percent of internal heat. Rigorous exercise in extremely hot dry air can dispose up to as much as 90 percent of the internal heat.

Where we have problems is when the hot air is highly saturated with moisture thereby bringing about a high level of humidity in the air. The moist air hinders the evaporation of sweat, hence, the heat from our bodies cannot escape through our skin as easily as it would in an air conditioned room. The rate of production of sweat outstrips the rate of evaporation and perspiration then collects on the surface of the body in visible drops. When that happens, we are hot and uncomfortable.

Many of us have seen pictures of soldiers lined up for an honour guard with one or more of the soldiers lying face down on the pavement with no-one making an attempt to bring them back to their feet. Believe it or not, leaving them on the pavement is by far kinder than standing them back on their feet. In fact, it has probably saved their lives.

If a person stands for any great length of time, especially in a queue on a particularly hot day, the veins in his legs expand as the body automatically tries to cool off in the day's heat. Then, as the upward blood flow from these distended vessels slows down, less blood reaches his brain and he becomes  giddy  and  might  very  well  faint—as  do  the  soldiers  in  the honour guards. If he continues to stand, his blood pools in his legs, thereby making it even  more  difficult  for  his blood to fight the gravitational pull. Eventually he loses consciousness and then collapses. That is what would save his life—if he didn't crack his skull in the fall. The worst thing that could happen if he began to fall is for some kind-hearted soul to sit him down on a bench. The blood would still be pooled in his legs and little of it would reach his brain. He might die from oxygen starvation in the brain--a serious result from heat prostration. Obviously, the best thing that can be done for such a person is to lay him down flat so that the blood can flow through his body again and thusly into his brain. This is why no one in the line attempts to lift him off the ground.

As mentioned earlier, heat prostration is a killer and as many as 15,000 Americans died from the effects of the 1980 heat wave that hit them that summer.

There are some very simple rules to follow when travelling in areas where the temperature and humidity is high.

1.     Drink plenty of fluids. Always carry a container of water with you.

2.     Wear something on your head. You don't want your brains fried in the process.

3.     Stop and rest when you feel dizzy and tired.

4.     Try to rent only rooms that are air conditioned.

5.    Take a cool bath or shower often in hot weather so that your surface body temperature will be lowered.

6.       Do not stand outdoors in long queues on hot humid days

7.       Avoid long walks unless absolutely necessary.

8.       Stay indoors if the city you are visiting is hit with a high degree of pollution in the air—especially if you are a smoker or suffer from a respiratory disease.

WARNING: If you are in a hot room with no airconditioning, do not sit in front of a fan if you haven't ingested a lot of water and have a glass of water within reach. If you fall asleep,the fan will keep evaporating the moisure from the surface of your body and more fluids in your body will rise to the surface until you become dehydrated and die.                

Do these precautions and you will live to tell everyone about your vacation. If not, then you, like thousands of others, may die on your holiday in a hot faraway place. 

In May, 1995, I was a speaker at the United Nations Congress on the Prevention of Crime being held in Cairo and sometime during the two weeks we were in Egypt, my wife and I visited Luxor which is about 600 miles south of Cairo and on the east bank of the Nile River. The summer season in Egypt is exceptionally hot during the months of May to August. The average temperature during the season of summer in the south rises up to 41 degree centigrade (106 degrees Fahrenheit).

When we visited that city, we visited the Temple of Queen Hatshepsut on the west side of the Nile. When we were at the temple and the Egyptologist who was the guide for me and my wife, was reading to us the Egyptian Hieroglyphic writings on the outside of the temple, I was feeling faint and felt that I was melting in the sun and my wife was uncomfortable in the sun also so obviously we needed shade as soon as possible, preferably air-conditioned shade which was a quarter mile from us.

I turned to the Egyptologist and said with a smile, “I can read Hieroglyphic writings quite proficiently. Would you like me to read those Hieroglyphics for you?”

He replied, "Please do."  

I pointed to the Hieroglyphics near the top of the temple and then said, “Tourists are melting in the sun. They need immediate shade.”

He looked at the writings and then turned to me and said with a big smile, “Sir. You really are proficient in reading Hieroglyphic writings. That’s exactly what it says. Let’s get out of the sun.”

If we had remained in the sun much longer, we all would have been in serious trouble.