6 effects of heat on the body

The effects of heat on the body appear when the body temperature regulation system begins to fail. If the failure continues, heat can lead to situations that put life at risk.

Humans have a body system prepared to maintain the temperature around 36 ºC. This body temperature is what allows organs to function normally.

When the temperature balance is broken, either up or down, unwanted effects appear. When the balance break is large, it manifests with pathological symptoms. Both hypothermia and hyperthermia can trigger death.

How the body controls the effects of heat

The human body has two main mechanisms to dissipate heat:

  • Increased blood flow to the skin: By causing vasodilation in the areas closest to the outside, the body causes heat exchange with the environment. This allows the excess heat to escape and does not have harmful effects on the organs.
  • Sweating:removes excess heat by evaporation. Sweat drops, when evaporated, cause the body to cool down. The human body is endowed with sweat glands capable of eliminating up to a liter and a half of sweat per hour.

When the environment is too hot, above 35 ° C, sweating can reach a limit. If the body detects that the loss of fluid and salts through sweat puts us in a dehydrating range, it will suspend transpiration.

At that point, it is possible that the effects of heat on the body that are listed below appear.

Sweating is a defense mechanism of the organism in the heat

To continue reading: Anhidrosis: inability to sweat

Effects of heat on the body

Bad breath

Dehydration, when present, affects all tissues of the body. One of the affected tissues is the oral mucosa. The oral mucosa, dehydrated, is responsible for dry mouth due to lack of saliva.

Without saliva, the bacteria proliferate, since one of the defensive mechanisms is exhausted. Those proliferating bacteria will cause bad breath or halitosis.

Heat cramps

Sweating not only removes fluid from the body, but also electrolytes and salts. The human body uses electrolytes for cellular operations. One of the tissues that most requires the salts is muscle tissue.

If the sweating is profuse and many electrolytes are lost, cramps may appear muscles or spasms in the extremities. It is an alarm sign; In case of heat cramps, physical activity should be stopped and hydrated. The next step, if not prevented, is exhaustion.

Heat exhaustion

When the necessary precautionary measures are not taken, the loss of liquids and salts through sweating can lead to body exhaustion, especially in situations of physical effort.

The symptoms of heat exhaustion are:

  • Tachycardia.
  • Generalized tiredness.
  • Irritability.
  • Hyperventilation.
  • Hypotension


This clinical situation is similar to heat exhaustion. It differs from him in that is caused by prolonged sun exposure. A person insolated is one in which the regulation mechanisms failed to be exposed to the sun for a long time.

The symptoms of heat stroke are:

  • Headache
  • Fatigue.
  • Facial congestion
  • Nausea and vomiting.
  • Thirst.

Prolonged exposure to the sun causes sunstroke

It may interest you: How to protect children from the sun


Syncope has different causes. One of them comes from the effect of heat on the body. Extreme heat causes too much vasodilation and redistribution of blood, which decreases its flow to the brain.

A syncope is a clinical picture produced by the inability of the blood flow to maintain the correct irrigation of the brain. When the amount of blood adequate to the brain does not come momentarily, oxygen does not arrive either; the central nervous system activates a regulation mechanism.

The regulation mechanism is the search of the horizontal position to improve cerebral blood flow. Because, the symptom of syncope is fainting. In general, it precedes blurred vision and wobbles.

The recovery is fast; When the body is horizontal, it recovers the blood flow to the brain.


The most serious form of the damaging effects of heat on the body is heat stroke. It can cause death; It is considered a medical emergency.

The first symptoms are those of heat exhaustion, or those of sunstroke. When these situations are not resolved in the short term, progress is made towards the heat stroke.

Up to 40 ° C body temperature the body is able to activate some defense mechanisms. If they exceed 41 ºC, the organism suspends its actions and stops working. The cells are unable to work in these conditions and can cause multi-organ failure.

Prevention of the effects of heat on the body

To avoid the effects of heat on the body, measurements are basic. Its fulfillment can avoid a fatal outcome. Prevention consists of:

  • Good daily hydration.
  • Do not expose yourself to the sun without protection and for long times.
  • Suspend work and exercise activities when symptoms of cramps or exhaustion appear.