Heat Exhaustion and the Dangers of High Temperature Exposure

Heat Exhaustion

What are Heat Related Illnesses?

Heat illnesses are often caused by dehydration and depleted electrolytes combined with hot and humid weather. When the body can’t cool itself by means of sweating it quickly overheats. Keep in mind that the normal body temperature sits around 98.6°F. When the core body temperature rises to critical levels past 103°F, such as in the case of developing heat exhaustion, there is an increased risk of sustaining long-term injuries or even resulting in death if the medical emergency is not treated promptly.

There are seven distinguishable heat related illnesses workers may suffer from. It must be noted that the following maladies do not occur in this specific order in the event of excessive heat exposure. This is because everyone’s body reacts to heat differently.

  1. Heat Rash – This is an uncomfortable condition of skin irritation that is the result of excessive sweating in hot, humid weather. The rash manifests as a cluster of red bumps on the neck, chest, groin, elbow creases, and other places where skin is touching skin.
  2. Heat Edema – This is one of the milder cases of heat illness a person can experience in which the hands and feet swell due to heat caused vasodilation and orthostatic pooling while standing or sitting for long periods.
  3. Heat Cramps – Excessive sweating in hot conditions saps the body of necessary salts called electrolytes. Combined with dehydration, the body can suffer from painful muscle cramps and spasms. This can also be a warning sign of impending heat exhaustion.
  4. Heat Syncope – A lack of acclimatization or dehydration can cause a fainting or dizzy spell after suddenly moving into a standing position from sitting or lying down due to a drop in blood pressure. The risk for physical injury after falling while unconscious can be serious, depending on where the individual is located.
  5. Heat Exhaustion – The excessive loss of water and salt combined with heavy physical exertion can result in heat exhaustion. The body temperature during this period is from 100.4 to 104.9°F. This is a serious medical condition that has the potential to lead to heat stroke, a deadly heat related illness.
  6. Heat Stroke – At this point the body has lost all control of its own body temperature. Characterized by a fever of more than 104.9°F, the individual has lost a significant amount of water which inhibits the body’s ability to sweat, an essential function that allows the body to cool itself. This condition has almost a 10% mortality rate even if a patient was diagnosed early and immediately cooled. When medical attention is delayed, it can kill as many as 80% of those who have been affected.
  7. Rhabdomyolysis – Both heat stress and dehydration amidst heavy physical activity can cause this condition. It is recognized by the rapid breakdown, rupture, and death of muscle. After muscle death, electrolytes and proteins are released into the bloodstream. This can cause an irregular heartbeat, seizures, and possibly even damage the individual’s kidney functions. This condition can cause a permanent disability or even death.

Whether or not a worker will survive one of the more serious cases of heat illness depends on two factors: how long they’ve been overheating and how quickly they can be cooled down. However, it must be noted that survival will not guarantee a full recovery due to possible complications. The key here is prevention.

Tip #1: Provide employees with enough water and frequent shade breaks when working outside in extreme heat.

What Causes Heat Related Illness?

There are several factors that can exacerbate the body’s thermoregulation mechanism. The following is a list of environmental conditions that often increase the risk of developing a heat-illness:

  • High temperature and humidity
  • Direct sun exposure
  • Indoor exposure to other sources of radiant heat
  • Limited air movement
  • Low fluid consumption
  • Physical exertion
  • Heavy personal protective clothing and equipment
  • Lack of recent exposure to hot working conditions
  • Previous heat-related illness

Notice that every one of these examples involves sweating. For example, high humidity and a lack of breeze does nothing to help us cool off because evaporation doesn’t occur as readily. A person also can’t sweat enough if they are dehydrated.

Tip #2: All bodies react differently to heat which means some tell-tale symptoms may not even appear until it’s too late. Because of this, workers and citizens can be overcome with heat exhaustion or heat stroke with hardly any warning.

Who is at Risk?

All people in high temperatures are susceptible to heat exhaustion. However, there are certain demographics that are more susceptible than others. These groups of people include those who are:

  • Under 4 or Older than 65 – Very young children and the older population are much moresusceptible to heat exhaustion and heat stroke as their bodies have a much more difficult time regulating temperature.
  • Taking Medications – Some medications lead to dehydration, and dehydration is one of the primary risks attributed to developing heat exhaustion. Heart medications and those that treat hypertension are two of the most common offenders.
  • Overweight – Excess body fat is excellent at retaining heat. Because of this, those who are overweight may find it extremely difficult to control their body temperature.
  • Not Accustomed to the Environment – Traveling from one place to another doesn’t just result in jet lag. Putting the body in a climate that it isn’t used to can be a shock in terms of acclimating to hotter temperatures. In fact, it takes on average 7 to 14 days to adjust to hotter temperatures.
  • Those in Poor Physical Condition or Have Health Problems – Diabetics, those with heart conditions, etc. are more susceptible to developing heat stress, whether it be because of the medication they take, or the condition of their health.
  • Pregnancy – Women who are pregnant are more likely to become dehydrated, it is also more difficult for them to cool off themselves and their unborn baby.

Tip #3: Pay close attention to those who are at a higher risk of developing heat exhaustion. It can happen fast without the victim even noticing something is wrong.

The Signs and Symptoms of Heat Illness

While heat exhaustion is different than heat stroke, the former can lead to the latter if the right measures aren’t taken to control the initial onset of symptoms. Let’s look at the different recognizable symptoms for each.

Those suffering from heat exhaustion may show the following symptoms:

  • Dizziness or feeling faint
  • Excessive sweating
  • Cool, clammy, or pale skin
  • Nausea or vomiting
  • A rapid or weak pulse
  • Severe muscle cramps

Now compare the heat exhaustion symptoms to those of heat stroke:

  • Headache
  • Dry, red skin
  • No sweating
  • A temperature over 104.9°F
  • A rapid, strong pulse
  • Unconsciousness

Now that each have been explained, you can go out into the field and be confident that you’ll be able to recognize heat exhaustion before it reaches the deadlier symptoms of heat stroke.

Tip #4: Heat illnesses don’t just happen outdoors during heat waves. Workers in hot and poorly ventilated indoor environments can suffer from heat exhaustion as well.

Dangerous Health Complications

If heat exhaustion is left untreated and escalates to the point of heat stroke, the afflicted individual only has a short period of time before life threatening complications occur. Of which include:

  • Renal failure
  • Pulmonary failure
  • Heart dysfunction
  • CNS dysfunction
  • Liver failure
  • Intravascular coagulation

As the body’s temperatures climb during a heat stroke, the body begins to rapidly deteriorate as follows:

  • At 105°F cells begin to generate heat 50% faster than normal due to an increased metabolism. This works to further increase the body’s temperature.
  • From 105°F to 106°F the individual may suffer from seizures.
  • 107°F to 109°F causes the victim to vomit and release their bowels.
  • 110°F to 111°F begins the stage where cells start to break down in both vital organs and muscle tissue. The victim may have blood in their vomit from hemorrhaging in their lungs and heart. All this internal damage also causes the circulatory system to develop blood clots as it thinks blood vessels have been severed.

If heat stroke doesn’t end in fatality, there is a large likelihood that the patient may suffer from one of these complications, changing their life permanently as well as shortening their lives significantly.

When to Seek Medical Treatment

Treating heat exhaustion quickly is essential to prevent it from escalating to a heat stroke. The best thing you can do is try and cool the worker as fast as possible.

The following three principles lay out exactly what to do in these situations:

  1. Move the worker to a shaded area or to a building with air conditioning. And encourage frequent sips of cool water.
  2. Work on cooling the individual quickly. This can be done by removing their outer clothing, placing ice on the head, neck, groin, abdomen, and armpits, using a fan to circulate the air around the worker, and in emergencies immersing them in water or an ice bath.
  3. Stay with the worker and monitor them until they recover. These emergencies can progress incredibly quickly and that means they could need more drastic cooling measures or the need to call 911.

Tip #5: A helpful mantra for these frightening situations that OSHA recommends, is “when in doubt, cool the worker and call 911.”

Prevent Heat Exhaustion and Heat Stroke
Under OSHA’s General Duty Clause, employers are required to provide a place of employment "free from recognized hazards that are causing or likely to cause death or serious harm to employees." This includes hot weather hazards such as heat exhaustion and heat stroke, of which are likely to cause serious harm and even death.

The following are excellent heat-illness prevention measures employers can use to improve their safety and health program:

  1. Train both workers and supervisors on the hazards that lead to heat illness, how to recognize the symptoms, how to prevent them, and how to treat heat exhaustion.
  2. Give workers time to adjust to the hotter environment. This applies to both new workers, as well as those who have missed work for a longer period. Acclimate them by gradually increasing the workload or allow for more frequent breaks in the first week.
  3. Provide workers with plenty of cool water in both convenient and visible locations. Water should be pleasant and odor-free with a temperature of 50-60°F if possible.
  4. Simply telling employees to drink plenty of fluids is not a sufficient reminder. Encourage them to drink small amounts of water often. During a moderate level of activity and heat, workers must drink about 1 cup every 15 to 20 minutes to stay hydrated.
  5. Instruct workers that urine should lightly colored. Too much water will result in clear urine which can mean over-hydration and too little water results in copper colored urine, a sign that they are severely dehydrated.
  6. Encourage workers to eat regular meals and snacks as these provide enough salt and electrolytes to replace those lost through sweating. Sports drinks are usually not necessary and should never replace water entirely.
  7. Set up a buddy system. If this is not possible, check on workers several times an hour to make sure they are drinking and utilizing shade when needed as well as to check for any heat exhaustion symptoms.
  8. Make sure employees know that there is such a thing as over-hydration. People should generally not drink more than 12 quarts (48 cups) in a 24-hour period. If this is happening, a more comprehensive heat illness prevention program is required.
  9. Reduce the physical demands of the job if possible during extreme instances of heat. If these types of tasks can’t be avoided, change work/rest cycles to increase the amount of rest time to prevent heat sickness.
  10. Schedule frequent rest periods with water breaks in shaded or air-conditioned recovery areas. Air conditioning will not result in loss of heat tolerance. In fact, it is recommended for breaks.

Remember, heat-illness prevention measures are the only way to reduce the risk of developing potentially deadly heat induced sicknesses. The employer must do everything they can to keep workers safe, and if that means working at different times during the day, monitoring the heat index, and taking more breaks for hydration, then it must be done.

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