Dehydration is when the loss of fluids is greater than the fluid intake. A loss of fluids affects the body’s ability to function normally and regulate body temperature.

Overview of dehydration

A loss of fluids affects the body’s ability to function normally and regulate body temperature. A major cause of dehydration is not consuming enough water. However, other causes can be fever, sweating too much, urinating too often, certain medications, diarrhoea and vomiting. Proper hydration is vital for the body to function, perform necessary biochemical reactions,get rid of infections without self-injury and also maintain the necessary homeostatic conditions such as nutrient balance in the body.¹

Importance of body temperature regulation

Water plays a crucial role in maintaining body temperature at an optimal level of 37℃. Maintaining an optimal body temperature is necessary for organ function, chemical reactions in the body such as enzyme function and cardiovascular health.²

Dehydration means that the body is less effective at cooling itself if it gets too hot. Sweating, which produces little droplets of water on the surface of the skin, is a means of cooling the body down if the temperature goes above 37.5℃. Abnormalities in the ability to sweat can result in a reduced quality of life, heat stroke, heat exhaustion, chronic electrolyte imbalance and reduced efficacy in controlling optimal body temperature.³

How does sweat help control body temperature?

Sweat as a cooling mechanism

The physics behind sweating is known as “the heat of vaporization”, which means that energy (ie heat) is used to convert liquid to vapour, which results in a loss of heat resulting in cooling.

Sweat production and fluid balance

Sweat is produced by sweat glands that exist in the skin known as the eccrine gland. They are more concentrated in certain areas like the armpits, feet and hands. Proper hydration is essential for optimum functioning of sweat glands. Wearing clothes that prevent the cooling effect, working in hot conditions or in humid conditions or excessive sweating during exercise without proper hydration can be detrimental to your health. 

What is fever and what function does it have in body temperature? 

A fever is an increase in temperature used by the body to control an infection and is often also used as a sign of a bodily infection.

Raising the body temperature creates a hostile environment for the invading bug and is a mechanism used to limit growth and spread of the infection,

A fever causes an increase in body temperature. To ensure that minimal harm is done to the body so that organs can function and all the necessary biochemical reactions continue, the body will initiate sweating. Sweating will result in cooling which will lower the body temperature.

How does dehydration impact body temperature management?

Reduced ability to control body temperature

If you are dehydrated, you won’t be able to sweat or will sweat very little and thus not lower the body temperature efficiently enough.

Longer fever time and higher fevers

If you cannot sweat, you cannot regulate the body temperature which means it could worsen and go on causing major complications such as?

Reduce the ability of the immune system to function properly

Dehydration ultimately affects the electrolyte balance, which includes micronutrient availability in the blood for essential biochemical reactions to occur.

How to manage a fever during dehydration?

Drinking enough water

Maintaining sufficient water intake is vital to ensure the body functions optimally. However, it is also important to not drink too much water and cause water intoxication.

Rehydration

Electrolyte solutions, intravenous fluids (IV drips), and drinking enough water are all means of ensuring you are hydrated.

Other cooling methods

In the interim, whilst waiting for your body to return to its normal ability to cool other means of cooling can be used. This could be removing layers of clothing, a cool cloth on the forehead, fan or aircon and increased ventilation as well as minimal physical activity or exertion. 

Tracking hydration and improving drinking habits

Ensuring that you drink enough water during the day is essential in improving hydration and reducing the risk of dehydration. Especially in the event of a fever or if you know you are unwell, ensuring that you take the relevant medical aids (such as electrolytes) and drinking enough water remain important in maintaining an optimal body temperature.

Summary 

• Proper hydration is key for good health 
• When sick ensure that you increase the amount of fluid
• If doing strenuous physical activity that results in a need for the body to sweat, ensure proper hydration 
• Dehydration can lead to strokes, organ failure, blackouts and other episodes with lasting medical health implications