The heatwave that is currently affecting some parts of the US is just the most recent in a string of extremely hot weather that has affected many parts of the world. As a result of this trend, the dangers of heat-related illness are becoming all too real.

In addition to harming animals, the intense heat is also having an impact on people. In recent years, heatwaves have claimed lives in Saudi Arabia, Europe, and India.

Sweating is one way the body attempts to cool off in the summer, but what happens if that doesn’t work?

Heat fatigue
Heat exhaustion and heat stroke are frequently discussed as though they are two distinct conditions. However, they range from a minor emergency to a serious, life-threatening one, according to emergency medicine specialist Dr. Thomas Waters in a Cleveland Clinic Health Essentials post.

Although it can develop into a more serious heatstroke if left untreated, heat exhaustion falls in the middle.

Excessive sweating is the primary early indicator of heat exhaustion, as the body makes a desperate attempt to cool itself by allowing perspiration to evaporate from the skin. The hypothalamus, a tiny area of the brain that controls body temperature, is what causes this. It stimulates the production of sweat by sending signals to the sweat glands through the nervous system.

However, this is insufficient to cool the body in heat exhaustion, and the core temperature of the body can rise to 38.3 to 40 °C (101 to 104 °F). It also gets harder to replenish all of the fluids and electrolytes lost during this phase of sweating, which increases the risk of dehydration and some other illness symptoms.

For example, the body needs minerals like potassium and sodium to properly function muscles, send nerve signals, and keep the volume of blood and fluids in check. Muscle spasms, lightheadedness, weakness, and an elevated heart rate to compensate for decreased blood volume can result from the loss of those vital electrolytes.

Similar to sweating, nausea and vomiting can also be signs of heat exhaustion because they are the body’s means of expelling heat-retaining material. “These are not only symptoms of heat exhaustion, but they can also complicate your recovery process when attempting to rehydrate,” a press release from Baylor College of Medicine stated about Isabel Valdez, a physician assistant and assistant professor of general internal medicine.

Overheating
Heat exhaustion can develop into heatstroke, a potentially fatal illness, if it is not treated or if the body is unable to cool down in 30 minutes. The body can no longer regulate its temperature at this point, and it can quickly rise above 40 °C (104 °F). Despite popular belief, people don’t always stop sweating at this point.

The authors of a review on the illness state that “extreme hyperthermia (usually >40.5°C [105°F]), multiorgan failure, and central nervous system (CNS) dysfunction are the clinical hallmarks of heatstroke.”

Regarding the central nervous system (CNS), which is made up of the brain and spinal cord, this can show up as obvious symptoms like disorientation, slurred speech, unconsciousness, or seizures. This is due to the brain’s heightened sensitivity to heat, as high temperatures can harm brain cells and result in their malfunction or death. This may be lethal or cause survivors to suffer irreversible, incapacitating injuries.

In heatstroke, problems with the central nervous system (CNS) can cause problems with other organs, but the immune system’s severe stress response also plays a significant role in the multiorgan failure that occurs.

It’s unclear exactly how the process operates, but the immune system’s response to overheating is an inflammatory response that affects the entire body. In other situations, a healthy amount of inflammation is beneficial for preventing infection or promoting the healing of wounds; however, in this instance, the response is excessive to the point where it can seriously harm the body and result in problems like kidney, liver, or heart failure.

Handling illnesses associated with heat
When suffering from heat exhaustion, it’s critical to remove any excess clothing as soon as possible, rehydrate (cold water and sports drinks are both beneficial for this), and use fans, cold packs, sprayed or sponged water, and other items to cool the skin. This can be carried out wherever the symptomatic individual is at that moment.

Heatstroke, however, is considered a medical emergency, and as such, medical assistance should be contacted.

It can turn lethal very fast. No matter how strong you are, heat stroke is something you cannot simply overcome, according to Dr. Waters. “Listening to your body and heeding warning signs is the most crucial thing you can do.”