Physical activity in extremely hot weather should be avoided. If a person starts to experience over heating, and symptoms of heat syncope, they should move or be moved to a shaded or cool area. It is also recommended to avoid alcoholic beverages in hot weather, because they cause dehydration which may worsen symptoms. Finally, drinking plenty of water is imperative when engaging in physical activity in hot weather.

The basic treatment for heat syncope is like that for other types of fainting: the patient is positioned in a seating or supine position with legs raised. Water containing salt, or another drink containing electrolytes, is administered slowly, and the patient is moved to a cooler area, such as the shade.

The affected person should rest and recover, because heat syncope can lead to heat stroke or heat exhaustion.

Brief periods of unconsciousness do no harm and are seldom symptoms of disease.

The main danger of vasovagal syncope (or dizzy spells from vertigo) is the risk of injury by falling while unconscious. Medication therapy could possibly prevent future vasovagal responses; however, for some individuals medication is ineffective and they will continue to have fainting episodes.

The underlying cause must be removed. Mild hyperthemia caused by exertion on a hot day may be adequately treated through self-care measures, such as increased water consumption and resting in a cool place. Hyperthermia that results from drug exposure requires prompt cessation of that drug, and occasionally the use of other drugs as counter measures. Antipyretics (e.g., acetaminophen, aspirin, other nonsteroidal anti-inflammatory drugs) have no role in the treatment of heatstroke because antipyretics interrupt the change in the hypothalamic set point caused by pyrogens; they are not expected to work on a healthy hypothalamus that has been overloaded, as in the case of heatstroke. In this situation, antipyretics actually may be harmful in patients who develop hepatic, hematologic, and renal complications because they may aggravate bleeding tendencies.

When body temperature is significantly elevated, mechanical cooling methods are used to remove heat and to restore the body's ability to regulate its own temperatures. Passive cooling techniques, such as resting in a cool, shady area and removing clothing can be applied immediately. Active cooling methods, such as sponging the head, neck, and trunk with cool water, remove heat from the body and thereby speed the body's return to normal temperatures. Drinking water and turning a fan or dehumidifying air conditioning unit on the affected person may improve the effectiveness of the body's evaporative cooling mechanisms (sweating).

Sitting in a bathtub of tepid or cool water (immersion method) can remove a significant amount of heat in a relatively short period of time. It was once thought that immersion in very cold water is counterproductive, as it causes vasoconstriction in the skin and thereby prevents heat from escaping the body core. However, a British analysis of various studies stated: "this has never been proven experimentally. Indeed, a recent study using normal volunteers has shown that cooling rates were fastest when the coldest water was used." The analysis concluded that cool water immersion is the most-effective cooling technique for exertional heat stroke. No superior cooling method has been found for non-exertional heat stroke. Thus, aggressive ice-water immersion remains the gold standard for life-threatening heat stroke.

When the body temperature reaches about 40 °C, or if the affected person is unconscious or showing signs of confusion, hyperthermia is considered a medical emergency that requires treatment in a proper medical facility. In a hospital, more aggressive cooling measures are available, including intravenous hydration, gastric lavage with iced saline, and even hemodialysis to cool the blood.

If a person with heat exhaustion gets medical treatment, Emergency Medical Technicians (EMTs) or doctors and/or nurses may also:

- Give them supplemental oxygen

- Give them intravenous fluids and electrolytes if they are too confused to drink and/or are vomiting

First aid for heat exhaustion includes:

- Moving the person to a cool place

- Having the patient take off extra layers of clothes

- Cooling the patient down by fanning them and putting wet towels on their body

- Having them lie down and put their feet up if they are feeling dizzy

- Having them drink water or sports drinks – but only if they are awake, not confused nor vomiting

- Turning the person on their side if they are vomiting

Medium-term (and less well-demonstrated) treatments of hypotension include:

- Blood sugar control (80–150 by one study)

- Early nutrition (by mouth or by tube to prevent ileus)

- Steroid support

Treatment for reflex syncope focuses on avoidance of triggers, restoring blood flow to the brain during an impending episode, and measures that interrupt or prevent the pathophysiologic mechanism described above.

Warm sweetened liquids can be given provided the person is alert and can swallow. Many recommend that alcohol and drinks with lots of caffeine be avoided. As most people are moderately dehydrated due to cold-induced diuresis, warmed intravenous fluids to a temperature of are often recommended.

IST has been treated both pharmacologically and invasively, with varying degrees of success. IST, in and of itself, is not indicative of higher rates of mortality, and non-treatment is an option chosen by many if they have minimal symptoms.

Some types of medication tried by cardiologists and other physicians include: beta blockers, selective sinus node I channel inhibitors (ivabradine), calcium channel blockers and antiarrhythmic agents. Some SSRI drugs are also occasionally tried and also treatments more commonly used to treat postural orthostatic tachycardia syndrome such as fludrocortisone. This approach is very much "trial-and-error". Patients with IST are often intolerant to beta blockers. A new selective sinus node inhibitor ivabradine is also being used to treat IST.

Invasive treatments include forms of catheter ablation such as sinus node modification (selective ablation of the sinus node), complete sinus node ablation (with associated implantation of a permanent artificial pacemaker) and AV node ablation in very resistant cases (creation of iatrogenic complete heart block, necessitating implantation of a permanent artificial pacemaker).

However invasive treatments can also make the symptoms worse, not cure it. Treatment should be chosen with care as the patient could become in need of a pacemaker or have more extensive symptoms.

Mild disease can be treated with fluids by mouth. In more significant disease spraying with mist and using a fan is useful. For those with severe disease putting them in lukewarm water is recommended if possible with transport to a hospital.

Prevention includes avoiding medications that can increase the risk of heat illness (e.g. antihypertensives, diuretics, and anticholinergics), gradual adjustment to heat, and sufficient fluids and electrolytes.

In those without signs of life cardiopulmonary resuscitation (CPR) should be continued during active rewarming. For ventricular fibrillation or ventricular tachycardia, a single defibrillation should be attempted. People with severe hypothermia however may not respond to pacing or defibrillation. It is not known if further defibrillation should be withheld until the core temperature reaches . In Europe epinephrine is not recommended until the temperature reaches while the American Heart Association recommended up to three doses of epinephrine before is reached. Once a temperature of is reached, normal ACLS protocols should be followed.

Most patients experience an improvement of their symptoms, but for some, OI can be gravely disabling and can be progressive in nature, particularly if it is caused by an underlying condition which is deteriorating. The ways in which symptoms present themselves vary greatly from patient to patient; as a result, individualized treatment plans are necessary.

OI is treated both pharmacologically and non-pharmacologically. Treatment does not cure OI; rather, it controls symptoms.

Physicians who specialize in treating OI agree that the single most important treatment is drinking more than two liters (eight cups) of fluids each day. A steady, large supply of water or other fluids reduces most, and for some patients all, of the major symptoms of this condition. Typically, patients fare best when they drink a glass of water no less frequently than every two hours during the day, instead of drinking a large quantity of water at a single point in the day.

For most severe cases and some milder cases, a combination of medications are used. Individual responses to different medications vary widely, and a drug which dramatically improves one patient's symptoms may make another patient's symptoms much worse. Medications focus on three main issues:

Medications that increase blood volume:

- Fludrocortisone (Florinef)

- Erythropoietin

- Hormonal contraception

Medications that inhibit acetylcholinesterase:

- Pyridostigmine

Medications that improve vasoconstriction:

- Stimulants: (e.g., Ritalin or Dexedrine)

- Midodrine (ProAmatine)

- Ephedrine and pseudoephedrine (Sudafed)

- Theophylline (low-dose)

- Selective serotonin reuptake inhibitors (SSRI's - Prozac, Zoloft, and Paxil)

Behavioral changes that patients with OI can make are:

- Avoiding triggers such as prolonged sitting, quiet standing, warm environments, or vasodilating medications

- Using postural maneuvers and pressure garments

- Treating co-existing medical conditions

- Increasing fluid and salt intake

- Physical therapy and exercise unless contraindicated by an underlying condition such as chronic fatigue syndrome where traditional exercise can worsen the condition

POTS treatment involves using multiple methods in combination to counteract cardiovascular dysfunction, address symptoms, and simultaneously address any associated disorders. For most patients, water intake should be increased, especially after waking, in order to expand blood volume (reducing hypovolemia). 8–10 cups of water daily are recommended. Increasing salt intake, by adding salt to food, taking salt tablets, or drinking sports drinks and other electrolyte solutions is an effective way to raise blood pressure by helping the body retain water. Different physicians recommend different amounts of sodium to their patients. Salt intake is not appropriate for people with high blood pressure. Combining these techniques with gradual physical training enhances their effect. In some cases, when increasing oral fluids and salt intake is not enough, intravenous saline or the drug desmopressin is used to help increase fluid retention.

Large meals worsen symptoms for some people. These people may benefit from eating small meals frequently throughout the day instead. Alcohol and food high in carbohydrates can also exacerbate symptoms of orthostatic hypotension. Excessive consumption of caffeine beverages should be avoided, because they can promote urine production (leading to fluid loss) and consequently hypovolemia. Exposure to extreme heat may also aggravate symptoms.

Prolonged physical inactivity can worsen the symptoms of POTS. Techniques that increase a person's capacity for exercise, such as endurance training or graded exercise therapy, can relieve symptoms for some patients. Aerobic exercise performed for 20 minutes a day, three times a week, is sometimes recommended for patients who can tolerate it. Exercise may have the immediate effect of worsening tachycardia, especially after a meal or on a hot day. In these cases, it may be easier to exercise in a semi-reclined position, such as riding a recumbent bicycle, rowing or swimming.

When changing to an upright posture, finishing a meal or concluding exercise, a sustained hand grip can briefly raise the blood pressure, possibly reducing symptoms. Compression garments can also be of benefit by constricting blood pressures with external body pressure.

If nonpharmacological methods are ineffective, medication may be necessary. As of 2013, no medication has been approved by the U.S. Food and Drug Administration to treat POTS, but a variety are used off-label. Their efficacy has not yet been examined in long-term randomized controlled trials.

Fludrocortisone may be used to enhance sodium retention and blood volume which may be beneficial not only by augmenting sympathetically-mediated vasoconstriction but also because a large subset of POTS patients appear to have low absolute blood volume.

While POTS patients typically have normal or even elevated arterial blood pressure, the neuropathic form of POTS is presumed to constitute a selective sympathetic venous denervation. In these patients the selective Alpha-1 Adrenergic receptor agonist Midodrine may increase venous return, enhance stroke volume and improve symptoms. Midodrine should only be taken during the daylight hours as it may promote supine hypertension.

Ivabradine can successfully restrain heart rate in POTS without affecting blood pressure and approximately 60% of POTS patients treated in an open-label trial of ivabradine experienced symptom improvement.

Pyridostigmine has been reported to restrain heart rate and improve chronic symptoms in about half of patients.

The selective alpha 1 agonist phenylephrine has been used successfully to enhance venous return and stroke volume in some people with POTS. However, this medication may be hampered by poor oral bioavailability.

The treatment for hypotension depends on its cause. Chronic hypotension rarely exists as more than a symptom. Asymptomatic hypotension in healthy people usually does not require treatment. Adding electrolytes to a diet can relieve symptoms of mild hypotension. A morning dose of caffeine can also be effective. In mild cases, where the patient is still responsive, laying the person in dorsal decubitus (lying on the back) position and lifting the legs increases venous return, thus making more blood available to critical organs in the chest and head. The Trendelenburg position, though used historically, is no longer recommended.

Hypotensive shock treatment always follows the first four following steps. Outcomes, in terms of mortality, are directly linked to the speed that hypotension is corrected. Still-debated methods are in parentheses, as are benchmarks for evaluating progress in correcting hypotension. A study on septic shock provided the delineation of these general principles. However, since it focuses on hypotension due to infection, it is not applicable to all forms of severe hypotension.

1. Volume resuscitation (usually with crystalloid)

2. Blood pressure support with a vasopressor (all seem equivalent with respect to risk of death, with norepinephrine possibly better than dopamine). Trying to achieve a mean arterial pressure (MAP) of greater than 70 mmHg does not appear to result in better outcomes than trying to achieve a MAP of greater than 65 mm Hg in adults.

3. Ensure adequate tissue perfusion (maintain SvO2 >70 with use of blood or dobutamine)

4. Address the underlying problem (i.e., antibiotic for infection, stent or CABG (coronary artery bypass graft surgery) for infarction, steroids for adrenal insufficiency, etc...)

The best way to determine if a person will benefit from fluids is by doing a passive leg raise followed by measuring the output from the heart.

When ambient temperature is excessive, humans and many animals cool themselves below ambient by evaporative cooling of sweat (or other aqueous liquid; saliva in dogs, for example); this helps prevent potentially fatal hyperthermia. The effectiveness of evaporative cooling depends upon humidity. Wet-bulb temperature, which takes humidity into account, or more complex calculated quantities such as wet-bulb globe temperature (WBGT), which also takes solar radiation into account, give useful indications of the degree of heat stress and are used by several agencies as the basis for heat-stress prevention guidelines. (Wet-bulb temperature is essentially the lowest skin temperature attainable by evaporative cooling at a given ambient temperature and humidity.)

A sustained wet-bulb temperature exceeding 35 °C is likely to be fatal even to fit and healthy people unclothed in the shade next to a fan; at this temperature, environmental heat gain instead of loss occurs. , wet-bulb temperatures only very rarely exceeded 30 °C anywhere, although significant global warming may change this.

In cases of heat stress caused by physical exertion, hot environments, or protective equipment, prevention or mitigation by frequent rest breaks, careful hydration, and monitoring body temperature should be attempted. However, in situations demanding one is exposed to a hot environment for a prolonged period or must wear protective equipment, a personal cooling system is required as a matter of health and safety. There is a variety of active or passive personal cooling systems; these can be categorized by their power sources and whether they are person- or vehicle-mounted.

Because of the broad variety of operating conditions, these devices must meet specific requirements concerning their rate and duration of cooling, their power source, and their adherence to health and safety regulations. Among other criteria are the user's need for physical mobility and autonomy. For example, active-liquid systems operate by chilling water and circulating it through a garment; the skin surface area is thereby cooled through conduction. This type of system has proven successful in certain military, law enforcement, and industrial applications. Bomb-disposal technicians wearing special suits to protect against improvised explosive devices (IEDs) use a small, ice-based chiller unit that is strapped to one leg; a liquid-circulating garment, usually a vest, is worn over the torso to maintain a safe core body temperature. By contrast, soldiers traveling in combat vehicles can face microclimate temperatures in excess of 65 °C and require a multiple-user, vehicle-powered cooling system with rapid connection capabilities. Requirements for hazmat teams, the medical community, and workers in heavy industry vary further.

Medications to treat CPVT include beta blockers and verapamil.

Flecainide inhibits the release of the cardiac ryanodine receptor–mediated Ca, and is therefore believed to medicate the underlying molecular cause of CPVT in both mice and humans.

Implantable cardioverter-defibrillators are used to prevent sudden death.

People with atrial fibrillation and rapid ventricular response are often treated with amiodarone or procainamide to stabilize their heart rate. Procainamide and cardioversion are now accepted treatments for conversion of tachycardia found with WPW. Amiodarone was previously thought to be safe in atrial fibrillation with WPW, but after several cases of ventricular fibrillation, it is no longer recommended in this clinical scenario.

AV node blockers should be avoided in atrial fibrillation and atrial flutter with WPW or history of it; this includes adenosine, diltiazem, verapamil, other calcium channel blockers, and beta blockers. They can exacerbate the syndrome by blocking the heart's normal electrical pathway (therefore favoring 1:1 atrial to ventricle conduction through the pre-excitation pathway, potentially leading to unstable ventricular arrhythmias).

People with WPW who are experiencing tachydysrhythmias may require synchronized electrical cardioversion if they are demonstrating severe signs or symptoms (for example, low blood pressure or lethargy with altered mental status). If they are relatively stable, medication may be used.

The medical literature suggests a number of treatments that have been proven effective for specific cases of needle phobia, but provides very little guidance to predict which treatment may be effective for any specific case. The following are some of the treatments that have been shown to be effective in some specific cases.

- Ethyl Chloride Spray (and other freezing agents). Easily administered, but provides only superficial pain control.

- Jet Injectors. Jet Injectors work by introducing substances into the body through a jet of high pressure gas as opposed to by a needle. Though these eliminate the needle, some people report that they cause more pain. Also, they are only helpful in a very limited number of situations involving needles i.e. insulin and some inoculations.

- Iontophoresis. Iontophoresis drives anesthetic through the skin by using an electric current. It provides effective anesthesia, but is generally unavailable to consumers on the commercial market and some regard it as inconvenient to use.

- EMLA. EMLA is a topical anesthetic cream that is a eutectic mixture of lidocaine and prilocaine. It is a prescription cream in the United States, and is available without prescription in some other countries. Although not as effective as iontophoresis, since EMLA does not penetrate as deeply as iontophoresis-driven anesthetics, EMLA provides a simpler application than iontophoresis. EMLA penetrates much more deeply than ordinary topical anesthetics, and it works adequately for many individuals.

- Ametop. Ametop gel appears to be more effective than EMLA for eliminating pain during venepuncture.

- Lidocaine/tetracaine patch. A self-heating patch containing a eutectic mixture of lidocaine and tetracaine is available in several countries, and has been specifically approved by government agencies for use in needle procedures. The patch is sold under the trade name "Synera" in the United States and "Rapydan" in European Union. Each patch is packaged in an air-tight pouch. It begins to heat up slightly when the patch is removed from the packaging and exposed to the air. The patch requires 20 to 30 minutes to achieve full anesthetic effect. The Synera patch was approved by the United States Food and Drug Administration on 23 June 2005.

- Behavioral therapy. Effectiveness of this varies greatly depending on the person and the severity of the condition. There is some debate as to the effectiveness of behavioral treatments for specific phobias (like blood, injection, injury type phobias), though some data are available to support the efficacy of approaches like exposure therapy. Any therapy that endorses relaxation methods may be contraindicated for the treatment of fear of needles as this approach encourages a drop in blood pressure that only enhances the vasovagal reflex. In response to this, graded exposure approaches can include a coping component relying on applied tension as a way to prevent complications associated with the vasovagal response to specific blood, injury, injection type stimulus.

- Nitrous Oxide (Laughing Gas). This will provide sedation and reduce anxiety for the patient, along with some mild analgesic effects.

- Inhalation General Anesthesia. This will eliminate all pain and also all memory of any needle procedure. On the other hand, it is often regarded as a very extreme solution. It is not covered by insurance in most cases, and most physicians will not order it. It can be risky and expensive and may require a hospital stay.

- Benzodiazepines, such as diazepam (Valium) or lorazepam, may help alleviate the anxiety of needle phobics, according to Dr. James Hamilton. These medications have an onset of action within 5 to 15 minutes from ingestion. A relatively large oral dose may be necessary.

Arrhythmia termination involves stopping a life-threatening arrhythmia once it has already occurred. One effective form of arrhythmia termination in individuals with LQTS is placement of an implantable cardioverter-defibrillator (ICD). Also, external defibrillation can be used to restore sinus rhythm. ICDs are commonly used in patients with fainting episodes despite beta blocker therapy, and in patients having experienced a cardiac arrest.

With better knowledge of the genetics underlying LQTS, more precise treatments hopefully will become available.

The tilt table test is an evaluative clinical test to help identify postural hypotension, a common cause of presyncope or syncope. A tilt angle of 60 and 70 degrees is optimal and maintains a high degree of specificity. A positive sign with the tilt table test must be taken in context of patient history, with consideration of pertinent clinical findings before coming to a conclusion.