Treating hyperthermia

Treating hyperthermia

Signs of heat stress, fatigue, cramps, oedema and rash can be managed without the need for medical intervention if attended to quickly enough. At the first signs of strain, both in a physical and mental well-being capacity, body temperature control can be managed without the need to panic.

The first thing to do is find a cooler location (e.g. find a shaded area) or activate a cooling mechanism such as a fan or air conditioner. Garments or clothing should also be loosened (restrictive or heavy fabric garments or accessories should be removed) to allow for easier breathing, especially if a person is wearing a tie or a neck scarf. Loosened or lighter clothing can help to increase comfort levels and aid the body in being able to cool down.

Fluids containing electrolytes and water (no alcohol or caffeine) should be taken in to help restore hydration in the body and replenish nerve and muscle tissues with calcium, sodium and potassium, and thus prevent heat-related symptoms from worsening. Sometimes eating a salty snack can help.

Cold compresses, ice packs or towels (or cloths) soaked in cold water can be applied to the forehead, back of the neck, wrist and under the arms to assist the body in cooling down to a safe temperature.

If exercising or engaging in activity, stop, especially if warning signs of syncope (fainting) develop. It is best to sit or lie down and elevate the legs higher than the head (restoring blood flow back to the brain and possibly prevent a fainting episode). This can also prevent the occurrence of injuries should passing out take place.

The affected body areas, especially if affected by rash should be kept as dry as possible. No ointments or creams should be applied to the skin to treat a heat rash as this will warm and moisten the skin further and worsen the condition.

Heat cramps can also be alleviated by slowly stretching affected muscles and a little gentle massage. If heat cramps occurred following exercise activity, a person should refrain from returning to the activity for a few hours once cramps subside.

Once the body’s nerves and muscles, as well as heart (pulse) rate return to normal function, temperature becomes more balanced and the body cools down.

Any signs of heat oedema typically resolve when the body’s regulatory system returns to normal or a person becomes used to a climatic adjustment (e.g. adjusting to conditions at a holiday location or after having moved to an area with a generally warmer climate). Oedema can be alleviated by elevating the lower legs and feet when swelling occurs.

When is a medical consultation for hyperthermia necessary?

Medical attention becomes necessary when syncope (passing out, fainting or blacking out) and signs of exhaustion or heatstroke occur.

A medical professional should be consulted if:

  • Overall symptoms do not subside within an hour (or worsen)
  • Signs of heat-related illness have been accompanied by fainting or loss of consciousness (especially if more than on one occasion) or feeling faint does not pass
  • Regaining consciousness has taken longer than 2 minutes
  • Seizures and confusion occur
  • A woman is pregnant or the affected person is a baby, small child or senior
  • Bladder or bowel control was lost when fainting occurred
  • Nausea and vomiting occur
  • Pulse rate or heartbeat became irregular or rapid
  • Any pain in the chest develops
  • The affected person has a history of or existing health condition (especially hypertension, hypotension, diabetes or heart disease)
  • Heat cramps do not subside within 1 hour

What will a doctor do about hyperthermia?

Upon arrival, a doctor will assess all symptoms and the nature of severity – is the person conscious and able to soundly communicate or is the person in advanced distress and requiring emergency treatment?

If the patient is able to answer, a doctor will ask questions relating to possible heat-related illness causes. He or she will wish to determine a person’s medical history (past or currently diagnosed conditions and possible use of medication or supplements, including herbal products).

A doctor will likely request that a person recount any events which lead to the build-up of the current condition (such as exposure to high heat or over-exertion of activity in hot conditions). A doctor will also wish to know if a fainting episode occurred and for how long consciousness was lost (this information may be obtained from a bystander who witnessed syncope).

A diagnosis of advanced phases of heat-related illness or hyperthermia (heat exhaustion or heatstroke) can often be diagnosed based on physical symptoms alone, obtained from a comprehensive physical examination.

A doctor, however, may wish to conduct several tests as a means to confirm a diagnosis or rule out any other associated conditions as a possible cause. These can include any of the following:

  • A blood pressure reading (learn more aboutwhat the two blood pressure numbers mean)
  • Rectal temperature reading: The most accurate measure of core body temperature is done taking a rectal reading (using a thermometer).
  • Muscle function test: This is to assess possible damage and breakdown of muscle tissues (leading to a condition known as rhabdomyolysis). Testing can be done in several ways. Manual testing is aimed at assessing muscle strength and whether a person can move a specific portion of their body against resistance. A doctor will look at individual muscles and muscle groups to determine their strength or identify a pattern of possible weakness. (1) Movement of muscles must normally be able to be performed to their greatest extent. Decreased movement could indicate weakness or damage to tissues. If a patient is able to, a doctor will request that they perform certain movements in order to make the assessment. Other valuation methods include handheld myometry, whereby a portable device is used to quantitatively measure the force of a particular muscle, as well as quantitative muscle testing / fixed system myometry, which involves a frame or wall mount with pulley attachments. 
  • Blood tests: A sample can be taken for analysis to check sodium and potassium levels in the body, and also to determine the level of dehydration and kidney function. Blood samples may also be analysed for content of gases in the bloodstream which may be an indicative marker of damage to the central nervous system. If relevant or necessary a woman may be checked for chances of pregnancy as well.
  • Urine sample: A sample of urine can also be analysed for signs of dehydration (usually evident by a dark yellow colour).
  • Tilt table test: This is an analysis of how heart function and blood pressure respond to various posture differences. A doctor will request a patient to begin by lying down on a table. Straps will then be placed around the body and after 10 to 15 minutes of lying flat the table will be tilted in various positions – e.g. the body may be raised to a head-up position (standing up). Each position will be maintained for a period of time and a person’s blood pressure and cardiovascular response monitored. Often this test may be used if the cause of an episode of fainting cannot be definitively determined or to rule out possible nervous system related explanations as to why blood pressure suddenly dropped.
  • Electrocardiogram (ECG or EKG): This is to analyse electrical activity in the heart and check for signs of an irregular heartbeat.
  • Imaging tests: In severe instances of hyperthermia if there are any suspicious signs of organ damage, an X-ray or ultrasound may be recommended.

Medical treatment for hyperthermia

In the case of more advanced phases of hyperthermia (heat exhaustion), a doctor will quickly administer treatment once the patient has been examined, tested, and a diagnosis is made. A person will be given rehydration fluids, intravenously (IV), especially in a heat emergency situation. The patient's airway must be assessed and protected, possibly by intubation (a process wherein a flexible tube is placed down the trachea in order to keep the airway open). Medical professionals will be very aware of possible seizures (removing all objects which can cause injury during a fit) and symptoms such as vomiting (clearing the airways and turning a person on their side to prevent choking) which can cause further complications and will treat these instances accordingly.

Other means of treatment are similar to those which can be done outside of a medical facility, but with very careful monitoring, particularly in the case of heatstroke.

Treatment other than the administering of IV fluids and the loosening (or removal of restrictive) clothing may include the following:

  • Cold water baths: It is important to lower core body temperature quickly so as to significantly reduce the risk of damage to the brain and tissues of vital organs (i.e. the heart, lungs etc.). One of the most effective ways to do this in a short space of time is by immersing a person in a cold bath of water. This will dramatically reduce the risk of bodily damage.
  • Evaporation cooling techniques: A cold water bath may not always be possible. In this instance, medical professionals will lower a person’s core body temperature using evaporation cooling methods. A person’s skin will be treated (sprayed) with a cool water mist, while warm air is fanned over them. This causes the water to evaporate and thus cool the skin and body temperature.
  • Ice packs and cooling blankets: Medical professionals may also opt to wrap a person in a specially made cooling blanket and apply cold compresses or ice packs around the neck, back, groin and armpit areas of the body.
  • Medications: If treatment techniques cause a person to shiver before core body temperature has reached a level of safety (normal), a doctor may administer a muscle relaxant to reduce the effect. Shivering will warm the body (as it is the body’s mechanism for warming core temperature) and thus counteract treatment objectives.

Once body temperature reaches about 38.8°C (102°F), a person will be considered out of the ‘danger zone’ and cooling methods may be tapered to prevent overcooling and potentially causing hypothermia. Once a person is stabilised, fluids may be given to drink (slowly) every so often (in approximately 15-minute intervals) in place of those administered via IV to rehydrate the body.

Woman sitting near a fan and cooling down.

Outlook for hyperthermia

Body temperature that has reached a hyperthermic state is of great concern to a person’s overall health condition. When medical intervention is required due to the body losing its capability of regulating (cooling) itself, emergency treatment received quickly enough can prevent serious damage to the body’s vital organs – heart, brain, kidneys etc. The longer treatment is delayed, the more complications (damage) can occur, and this increases the risk of a life-threatening situation.

With adequate treatment, most cases can be resolved quickly and a person can make a full recovery, returning to a completely healthy state. Any symptoms of hyperthermia which cannot be alleviated with self-treatment should be assessed by a medical professional for assistance.


1. National Center for Biotechnology Information. 26 May 2017. Muscle Strength Grading: Accessed 12.02.2018]

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