DEALING WITH THE HEAT

Facts and Tips on Managing Excess Heat Conditions in Nigeria

Picture credit: google images

Few organisms can survive extreme temperature conditions and they are perhaps fictional superhero characters living in the dark realms of the Art Illustrator’s imagination. Yet frankly, can you actually imagine a situation where normal life on earth is living in subzero temperature or near a hundred degree Celsius. Scary, right?

To say since these past months (starting from later parts of 2018), the country has been experiencing unprecedented warm ambience will be a huge understatement.

You recall similar situation has plagued other parts of the world. In fact, reports from popular media channels hinted that temperature has been rising and peaked at an all-time high (around 48 degree Celsius) resulting in natural disasters as wild fires, health complications and increased death toll not to mention increased financial burden to individuals and the government. Let me quickly add that it has not all bad news as certain fruit crops actually depends on the hot, dry weather for maturation, so its good news for these farmers.

As crucial as the term - temperature is to human activity, we’d fare well living within the optimum range - anything below and above might threaten our survival as a species.

The right temperature is vital for all normal biological functions I’ll broadly categorized as metabolic processes in the body. Perhaps you can you recall the acronym M.R. N.I.G.E.R. D? some science-based scholars have even supported the claim that humans and other advanced mammals may be less susceptible to many microbial infection (notably fungal species) compared to many reptiles due to our unique body temperature.

Well, in the process of living our normal lives, the metabolic processes of our bodies generate heat which inn one way or the other adds to the extant heat generated from environmental activities like irradiation from the sun, combustion of fossil fuel etc.

Presently, the world is experiencing incredulously high temperatures notably due to the greenhouse effect – a phenomenon describing the warming of the surface and lower atmosphere of a planet due to conversion of radiation from the sun into heat.

In Nigeria and many sub-Saharan countries, the Harmattan is expected to bring in hot dry weather yet one thing is evidently missing – the intermittent coolness of the wind that characterize the Harmattan. The heat wave is here and its monstrous presence is evidently suffocating bringing a lot of discomfiture all day long especially at night.

Unfortunately, the infrastructure of electricity which could have served to ameliorate the effect of the suffocating heat wave is still far from adequate.

Each government regime keeps making promises to do better while the deleterious effects of the heat waves sweeps on, through the urban centres unforgivingly. God help us – particularly those living in zones faced with additional poor housing infrastructure and population explosion.

Moreover, there’s also been public health concerns regarding the issue of insufficient heath centres to manage cases of heat – related illnesses or health workers to educate the general public on how to cope with the natural temperature rise.

In spite of these vastly economic factors, you can bet one of the advantages of being born and bred in the tropics known for its usual elevated temperature is that naturally, our bodies are well-adapted to the hot environment thanks to the naturally efficient heat – controlling mechanisms of our bodies.

Yet even with these natural superhero capabilities, we are entirely not immune to adverse effects from heat-related illnesses. One of such medical condition is known as HEAT STROKE.

So…with the intimidating wave of heat slowly slithering through the steady-polluted city landscape, it is not uncommon to hear people complain of cramps in their body extremities; headache; dizziness, clumsiness; restlessness and confusion (or delirium); hot, flushed, and dry skin; difficulty in breathing; convulsion; coma among others.

Do you reside in the tropics? Have you experienced any effects of the heat wave yet?

Heat stroke is sometimes associated with names like sunstroke, heat apnea. It is a medical condition resulting from rapid increase in body temperature above forty-degree Celsius.

Naturally, the human body system is designed to function at a temperature of between 36-degree Celsius and 37.5-degree Celsius (96.8-degree Fahrenheit and 99.5-degree Fahrenheit). This temperature range is kept constantly within these limits by a heat-regulating mechanism in the brain (precisely, the hypothalamus).

Occasionally, our body temperature can rise or fall to a level wherein this mechanism can no longer effectively regulate the temperature, resulting in the following conditions including hypothermia (too low body temperature) or hyperthermia as in the case of heat exhaustion and heat stroke.

It is important to note here that although heat (or temperature elevation) is involved, it is possible to suffer from heat exhaustion (which is different from heat stroke), although heat exhaustion could lead to heat stroke. In many cases, heatstroke follows when sweating ceases and the body cannot be cooled by the evaporation of sweat. You can get more information on heat exhaustion below.

In the hottest parts of the year, the heat wave could lead to increased risk to heat-induced illnesses (like heat exhaustion, heat cramp, heat stroke) causing high incidences of ailments (most notably, neurological complications) and death.

Causes of heat stroke?

One thing, you need to know - Heat related illnesses can affect anyone. The United Nations gazette on Climate Change have highlighted that chronic alcoholics, the elderly, the young, the obese and individuals with compromised immune systems are at greater risk of being affected.

The risk of have heat-induced illnesses is also heightened in individuals taking certain drugs such as antihistamines, antipsychotic medications and cocaine. High humidity can also increase the risk of heat illness because it interferes with the evaporation of sweat, your body’s way of cooling itself.

It is also important to note that those who have certain medical conditions that decrease the body’s ability to sweat – such as scleroderma or cystic fibrosis – may be at greater risk of developing heat stroke.

Also, certain occupations that expose persons to hot or humid environments such as manufacturing plants, bakeries or construction sites increase the risk of heat-related illnesses.

With respect to heat stroke, physical activities such as vigorous exercise and overexposure to heat (in the context of global warming) have both implicated as major causes of the condition.

What happens to the body during heat stroke?

During initial stages of heat stroke, the body homeostatic process in the hypothalamus is activated. The body tries to get rid of the excess heat by fostering vasodilation of the blood vessels with the skin and evaporation, which usually lead to loss of large volume of sweat to eliminate the heat which may be responsible for the dehydration experienced.

As in the other heat related illnesses; as your body works to cool itself under extreme or prolonged heat, blood naturally rushes to the surface of your skin. Consequently, less blood reaches your brain, muscles and other organs. This can interfere with both your physical strength and your mental capacity, leading in some cases to serious danger. Failure of the heat-control centre of the brain to regulate body temperature; the body becomes dangerously overheated.

In extreme cases of temperature elevation in the body, the body is poised to adapt to the temperature differences by activating immunological reactions like acute phase response, activation of endothelial, epithelial cells and leukocytes. This is aimed to protect the body tissue damage and promote cell repair.

Diagnosis: what do the medics tell us?

The basis for the diagnosis depends on an history of exposure to sunlight or strenuous exercise, increase in body temperature above 40 ° C and injury to the central nervous system (CNS).

All patients are known to experience tachycardia (increased heart activity whether physiological i.e. after exercise or due to pathological causes) and hyperventilation.

The extent of the toxic effect of heat is far-reaching affecting the gastrointestinal, hormonal and circulatory systems, the heart, lungs, kidney, liver. The heat stress also adversely affects the body immunity.

Scholarly reviews have claim that there was indeed a relationship between elevated temperature and cellular function. They pointed out that deterioration of cellular function may ensue as temperature increases culminating in cell necrosis and disruption of cellular metabolism. For instance, in a study using an animal model of heat stroke, baboons were subjected to elevated temperatures. 

It was found that there is damage to the ultrastructure characterized by extensive hemorrhage and thrombosis, as well as transmural leukocyte migration and microvascular endothelial damage; Immunohistochemistry showed increased endothelial von Willebrand factor and endothelial interaction of leukocytes and platelets. The histochemistry further revealed extensive apoptosis in spleen, intestines, lungs and hematopoietic cells. All this suggests that there may be microvascular injury, thrombosis, inflammation and ultimately apoptosis.

Interestingly, neurological injury is one of the most important diagnostic criteria of heat stroke and in both cases of heat stroke (post-exercise and classic), the nervous system is the first system affected, notably, the central nervous system. Cellular damage appears at the spinal, cerebral and cerebellar levels. The Purkinje fibers are sensitive to the toxic effects of heat.

With respect to the cardiovascular system, the electrocardiographic data reveals secondary myocardial ischemia as well as atrioventricular conduction disturbances, which further leads cardiovascular failure in severe cases.

At gastrointestinal level, heat stress leads to development of ulcers and bleeding favoring endotoxemia. In the liver, the heat stress leads to hepatic necrosis and cholestasis.

In the blood, the toxic effect of heat results to reactive leukocytosis; thrombosis; decreased synthesis of coagulation factors (due to hepatic dysfunction); intravascular coagulation with severe thrombocytopenia.

In the endocrine system, the effect of heat leads to secondary endocrine manifestations, the most frequent involves disturbances in metabolic activities. In classic HS, there is manifestations of hyperglycemia and elevations of serum cortisol. High levels of aldosterone and somatostatin may develop to preserve the blood volume.

Other complications include: respiratory alkalosis, lactic acidosis, electrolyte imbalance (as a result of dysfunction within the cells of the muscle, involving potassium, calcium, phosphorus, magnesium), respiratory distress syndrome, cardiac failure leading to pulmonary edema. Muscular degeneration and necrosis due to direct effect of heat, being more intense in the HS after exercise. Incidence of irreversible renal failure due to rhabdomyolysis, nephropathy and myoglobinuria.

Tips for managing heat stroke: what can be done?

The management of heat stroke is targeted at cooling the body in the shortest possible time (within 30-60 minutes into heat stroke or when diagnosis is made) and that depends on the level of the involvement of the vital organs.

By reducing excessive exposure to high temperatures and taking other precautionary steps, most heat related illnesses can be avoided.

(1) Quickly move the casualty to a cool place. Remove as much of his outer clothing as possible. Call medical help immediately.

(2) While waiting for emergency help, assist the casualty to sit down, supported with cushions. The best way to cool the casualty is to spray him with water and then fan him, repeatedly. A cold, wet sheet may also work, and ice packs in the armpits and groin may be effective.

(3) Once the casualty’s temperature appears to have returned to normal, replace the wet sheet with a dry one.

(4) Monitor and record vital signs—level of response, breathing, pulse, and temperature—while waiting for help. If the casualty’s temperature rises again, repeat the cooling process.

Other important Information

Heat exhaustion usually develops gradually and often affects people who are not acclimatized to hot, humid conditions. It is caused by loss of salt and water from the body through excessive sweating. The loss of salt because of excessive sweating may cause painful muscle cramps. A dangerous and common cause of heat exhaustion occurs when the body produces more heat than it can cope with. Some illicit drugs, such as ecstasy, can affect the body’s temperature regulation system. This, combined with the exertion of dancing in a warm environment, can result in a person becoming overheated and dehydrated. These effects can lead to heatstroke and even death. Some of the characteristics of heat exhaustion include; sweating; pale, clammy skin; cramps in the arms, legs, or abdomen; rapid, weakening pulse and breathing, in addition to symptoms experienced in heat stroke.

Tips in managing heat exhaustion

- Help the casualty to a cool, shady place. Get him to lie down and raise and support his legs to improve blood flow to his brain.

- Give him plenty of water to drink. Oral rehydration salts will help with salt replacement. About one teaspoonful of salt per litre of water should be sufficient.

- Monitor and record vital signs—level of response, breathing, and pulse. Even if the casualty recovers quickly, advise him to seek medical help.

- If the casualty’s vital signs worsen, call for emergency help. Monitor and record vital signs—level of response, breathing, and pulse—while you are waiting for help to arrive.

Source:  (i) American college of Emergency Physicians (DK 5^th First Aid Manual). (ii) del Carpio L (2015). Heat Stroke Review. MEDtube Science. Volume 3 (4): 17 – 23. (iii) www.aikenstandard.com (iv) www.webmd.com.

I hope this information was useful. Protect yourself…Protect the Earth. Share the message.

Cheers

Written by: Adedoyin Shobo