Sweating is the most effective cooling system of the body. It is used not only to cool the body but also to remove toxic wastes from the body. Due to excessive heat generated in the body, the cooling mechanism tries to cool the system down by excessive sweating. Due to this, the person is seen precipitating much more than usual. Sometimes, unchecked and excessive sweating leads to dehydration and consequent results.

Due to excessive sweating, the body loses vital nutrients in the sweat more than necessary. If this loss is not compensated, the person starts to feel weak and lethargic. This weakness is true weakness in case of heat exhaustion and is very less linked with the person’s psychology. The person starts to feel lack of strength in the muscles and dizzy. In some cases, the person becomes bedridden for days.

Muscles require some amount of water, glucose and metals (sodium, magnesium, calcium and potassium) for proper functioning. Due to excessive sweating, the level of water, glucose and metal-contents in the body goes down. Due to the reduced components, the muscles cannot expand and contract properly, making them irritable and leading to muscle cramps.

Due to the loss of vital nutrients and fluids from the body in sweating, nervous system is directly and indirectly affected. Increase in pressure in the nervous system, coupled with lack of fluids and nutrients for proper functioning, leads to strain in the system causing headache. Sometimes, in heat exhaustion, pressure comes on the heart to pump more blood suddenly, leading to abnormal blood-distribution. This further leads to fluctuation in the oxygen-levels received by the brain, leading to headaches. Overworked muscles also aggravate the matter.

Due to excessive sweating, the body loses more nutrients and fluids than usual, leading to malfunctioning of various systems. It affects proper functioning of the brain and digestive system as well. As the brain uses up more oxygen than what is actually available, it finds itself wanting for more, leading to nausea and fainting. Nausea sometimes precedes vomiting. It occurs due to the depletion of nutrients and fluids required to keep muscles in the digestive system (such as esophagus and stomach) operational in a proper manner. Due to the lack of nutrients, the muscles in the region become irritable, especially in the stomach, leading to vomiting.

Due to excess sweating, loss of fluids and nutrients take place. The loss is usually compensated by the body for a time but if the loss is not taken care of within a defining time-frame, the body goes in the dehydration-state. In this situation, the person starts experiencing headache, low blood-pressure and dizziness. He/she starts to see snow-like features in front of their eyes (also known as “visual-snow”). If untreated, dehydration leads to delirium, unconsciousness and death. It is one of the main symptoms of heat exhaustion, and is quite fatal in itself. 

A person suffering from heat exhaustion faces a rise in the body temperature up to 104 F. This is due to the excessive heat that gets trapped in the body due to its inability to disburse off the heat along with the heat generated from overused muscles to keep the body functioning. In the beginning, the fever is manageable and under control. If heat exhaustion is not treated, temperatures continue to rise until it crosses 104 F. From there, it spirals out of control, leading to serious consequences such as heat stroke and coma.