Heat Intolerance: Symptoms, Treatment, and Preventative Steps
Medically reviewed and edited by Most people don’t like extreme heat, but many individuals may find themselves experiencing intense levels of discomfort as the weather gets warmer.
This can be a sign of heat intolerance, a common condition that occurs due to the body’s inability to regulate its temperature properly.
Heat intolerance can be disruptive and challenging to deal with, especially if you don’t know its underlying cause.
In this article, we help you understand the factors that can contribute to heat intolerance, the available treatment options, and what you can do to reduce the impact of this condition on your daily activities.
What is Heat Intolerance?
Heat intolerance is a medical condition characterized by an unusual hypersensitivity to warmer temperatures.
Compared to others who find hot weather mildly uncomfortable, individuals with heat intolerance typically experience extreme discomfort and adverse reactions to it.
If you’ve ever experienced a bout of heat stroke, it means that the mechanisms in your body that typically regulate its internal temperature — like sweating — either overreacted or didn’t work well enough.
This then might have temporarily led to an inability to further withstand the warm environment comfortably.
However, unlike heat exhaustion or heat strokes — which are acute responses to extreme heat and can affect anyone — heat intolerance is a chronic condition.
It can develop due to various underlying causes, including genetics, health conditions, and medication side effects.
Symptoms of heat intolerance
The symptoms of heat intolerance can vary, but most people with this condition typically experience the following:
Excessive sweating
Fatigue and weakness
Dizziness
Lightheadedness
Rapid heartbeat
Headaches
Nausea
Muscle cramps
Irritability or mood changes
These symptoms will usually appear if you find yourself in a warm environment or area with a particularly hot climate.
Key Point: What is the Difference between Heat Intolerance and Heat Exhaustion?
Heat intolerance and heat exhaustion are related but distinct conditions.
Heat intolerance refers to a sensitivity to warm temperatures, leading to discomfort or adverse symptoms, even in less extreme heat.
It’s a chronic sensitivity that is usually diagnosed by a medical professional and often requires personalized treatment.
Heat exhaustion is a heat-related illness resulting from the body overheating, typically in high temperatures or through physical exertion. It can cause symptoms like heavy sweating, weakness, and nausea.
Unlike heat intolerance, which is a chronic condition that only affects certain people, heat exhaustion is an acute response to environmental factors that anyone can experience.
Heat exhaustion usually doesn’t require a professional diagnosis or treatment, unless it’s a severe case.
Causes of Heat Intolerance
Underlying medical conditions
There are a few medical conditions that can contribute to heat intolerance.
However, it’s important to note that developing heat intolerance symptoms does not mean you necessarily have any of the conditions outlined below.
You can speak to your doctor about getting a professional diagnosis if you have any health concerns.
Hyperthyroidism
Hyperthyroidism is a condition that develops when the thyroid produces too much of the hormone thyroxine.
Besides playing a vital role in brain development, heart and muscle function, and bone maintenance, the thyroid hormone also increases your basal metabolic rate (BMR) — or the speed at which the body metabolizes food.
This can raise your body temperature and cause you to feel warmer, even when the weather is mild.
In warm temperatures, individuals with hyperthyroidism may sweat excessively and start to feel an extreme sense of discomfort.
Multiple sclerosis (MS)
MS is an autoimmune disease affecting the central nervous system, which comprises the brain and spinal cord.
This disease affects and damages myelin — the protective covering of nerves — leading to interrupted nerve signals in the body.
When the brain can’t send the correct signals to nerves, it can cause various health implications, including heat intolerance.
Medication
One of the most common causes of heat intolerance is the use of certain medications that may increase heat sensitivity in warmer temperatures. These medications include:
Antihistamines
Anticholinergics
Diuretics
Stimulants
ACE inhibitors
Antidepressants and antipsychotics
Diabetes medication
Parkison’s drugs
Antibiotics
Appetite-suppressants
These medications can influence how your body cools down and may inhibit sweat production, causing discomfort in warm weather.
Caffeine sensitivity
Caffeine is a stimulant that can increase your heart rate and speed up your BMR.
This can cause your body temperature to rise, leading to sweating and discomfort in high temperatures.
Individuals with caffeine sensitivity may feel even warmer or more uncomfortable in hot environments after having consumed products that contain this substance.
How is Heat Intolerance Diagnosed?
When determining whether you have heat intolerance, your healthcare provider should take a comprehensive approach to ensure an accurate diagnosis.
You can typically expect the following during this process:
Medical history review: The first step in diagnosing heat intolerance involves your doctor reviewing your medical history. This includes discussing your symptoms, when they occur, how severe they are, and any factors that may make them worse. Your doctor will also ask about any existing medical conditions, medications, and a family history of similar symptoms.
Physical examination: After your doctor has reviewed your medical history, they will perform a physical examination. This involves checking for signs of dehydration, examining the thyroid gland for abnormalities, or assessing for any neurological impairments.
Specific tests: Depending on the outcome of your physical examination, your doctor may also recommend specific tests to help them make an accurate diagnosis. These may include blood tests, thyroid function tests, nerve conduction studies, and MRI scans.
Once the process has been completed, your doctor will make a diagnosis based on an analysis of your test results.
They will also recommend treatment options that can help you manage heat intolerance and live a normal life.
In some cases, you may also be referred to a specialist for a more targeted and individualized treatment plan.
What are the Treatment Options for Heat Intolerance?
Heat intolerance can usually be treated, depending on the underlying cause of your condition.
In most cases, treatment is used to alleviate your symptoms and help improve your tolerance to warmer temperatures.
Lifestyle changes
Making specific lifestyle changes can significantly reduce the impact of heat intolerance on the body. These changes may include:
Drinking plenty of fluids to stay hydrated
Wearing loose, lightweight clothing that keeps the body cool
Limiting your exposure to heat – such as avoiding being outside between 10 a.m. and 3 p.m.
Gradually increasing the time you spend in warm conditions to help your body adjust to the heat
Your doctor may recommend other specific lifestyle changes based on the cause of your heart intolerance.
Environmental adjustments
Your environment has the biggest impact on how you experience heat intolerance.
Ensuring that you’re in a comfortable space where you can stay cool is key and can be achieved by making the following adjustments:
Using fans or air conditioning to keep your living and working spaces cool, especially during the hottest parts of the day
Seeking shade as much as possible when outdoors to reduce direct exposure to the sun
Taking cool baths or showers to quickly lower the body’s temperature for immediate relief from discomfort
These strategies can help you relieve your heat tolerance symptoms and reduce their impact on your daily life.
Medication
In some cases, adjusting or changing the medications that contribute to heat intolerance can help you manage your symptoms.
This usually involves reviewing your current medications with your doctor and discussing possible alternatives or dosage adjustments.
If you’re not taking any medication to treat any of the underlying conditions that may be causing your heat intolerance — such as hyperthyroidism — it’s advised that you speak with your doctor.
They can recommend appropriate drugs that can help you manage these conditions, which could potentially help relieve your symptoms.
Can Heat Intolerance Be Prevented?
While it’s not possible to prevent heat intolerance completely, there are a few strategies you can implement to alleviate your discomfort.
Staying cool in hot weather
The primary way to prevent symptoms of heat intolerance is to take proactive steps toward staying cool in hot weather.
Apart from seeking shade when outside or avoiding sun exposure during the hottest times of the day, you can also consider using cooling products.
These products include items like cooling towels, fans, and misting sprays that can help bring your body temperature down and provide immediate relief.
Prioritize hydration
Staying hydrated is essential for regulating your body temperature and preventing heat-related illnesses and issues
You can do this by ensuring that you consume enough water throughout the day, especially during and after heat exposure.
It’s also recommended to limit your intake of dehydrating fluids — like coffee and alcohol — which can contribute to a flare-up of your symptoms.
Consuming these beverages may also increase your body temperature and exacerbate heat intolerance symptoms.
Dietary changes
The foods you eat can also influence your body’s ability to regulate heat, so making the right dietary choices is key. This can include:
Opting for smaller, lighter meals that are easier to metabolize
Choosing foods that have a higher water content — like fruits and vegetables — to help keep you hydrated
Avoiding spicy foods on warm days
These strategies can help you keep your BMR stable, which prevents a sudden or unnecessary increase in body temperature that may cause discomfort.
Potential Complications of Heat Intolerance
Depending on the underlying cause of your heat intolerance, you may be at risk of developing various complications.
For example, individuals with MS who experience heat intolerance may develop vision problems due to distorted nerve signals.
Other potential complications may include developing heat exhaustion, which can lead to symptoms like:
Confusion
Loss of consciousness
Vomiting
Muscle cramps
Elevated heart rate
Body temperatures of 104ºF or higher
Rapid breathing
If you experience any of these symptoms or complications, it’s important to seek medical attention immediately.
Many heat-related conditions and responses can be fatal if left untreated, so taking prompt action is key.
Where Can You Learn More About Managing Heat Intolerance?
If you’re concerned about your symptoms or want to know more about treating heat intolerance, LifeMD is here to help.
LifeMD can connect you to a team of medical professionals who can assist you with information and provide guidance on managing heat intolerance to avoid further complications.
Make an appointment with LifeMD today to learn more about heat intolerance care — all from the comfort of your home.
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