Low heat tolerance, or heat intolerance, is an unusual sensitivity to heat that causes adverse reactions at temperatures others find comfortable. This is a physiological response indicating the body is struggling to regulate its internal temperature. The body’s temperature is managed by the hypothalamus, a part of the brain that controls cooling. When the body gets too warm, the hypothalamus signals the skin to increase sweat production, and the evaporation of this sweat cools the body.
Common Symptoms of Heat Intolerance
A primary symptom is excessive sweating, though some people may paradoxically experience a lack of sweating. Physical reactions include headaches, dizziness, weakness or fatigue, nausea, muscle cramps, and a rapid heartbeat. Heat intolerance can also affect mental states, leading to irritability and difficulty concentrating. These symptoms may appear gradually but can persist for a day or two after exposure.
In some cases, heat intolerance can lead to more serious complications like heat exhaustion. The symptoms of heat exhaustion include confusion, vomiting, and a body temperature of 104°F (40°C) or higher. For those with multiple sclerosis, heat can temporarily worsen their symptoms, including vision problems ranging from blurred vision to temporary loss of sight. This is a phenomenon known as Uhthoff’s phenomenon.
Potential Causes of Low Heat Tolerance
Certain medical conditions affect the body’s ability to regulate temperature. For example, hyperthyroidism, where the thyroid gland produces too much thyroxine, can increase the body’s metabolism and lead to a higher body temperature. Graves’ disease, an autoimmune disorder, is a common cause of hyperthyroidism.
Multiple sclerosis (MS) is another condition that can lead to heat intolerance. MS is an autoimmune disease that damages the protective covering of nerves, which can disrupt nerve signals involved in temperature regulation. Other conditions like diabetes and dysautonomia can also be contributing factors.
Medications are a frequent cause of heat intolerance. Drugs such as antihistamines, decongestants, and diuretics can interfere with the body’s cooling mechanisms. Some psychiatric medications, including certain antidepressants and antipsychotics, can reduce the body’s ability to sweat.
Lifestyle factors also influence heat tolerance. Obesity, poor physical fitness, and a lack of acclimatization to hot environments can make it more difficult for the body to cool itself. Dehydration is another factor, as is the consumption of caffeine and alcohol.
Coping Mechanisms and Lifestyle Adjustments
Controlling your environment is a primary way to manage heat intolerance. Use air conditioning and fans to maintain a cool indoor space and take cool showers for immediate relief. It is also advisable to avoid being outdoors during the hottest parts of the day, between 10 a.m. and 3 p.m.
Clothing choices also make a substantial difference. Opting for lightweight, loose-fitting, and light-colored clothing made from breathable fabrics helps keep the body cool. These materials allow for better air circulation. When outdoors, seeking shade reduces direct sun exposure.
Proper hydration is another component of managing heat intolerance. Drink plenty of water to prevent dehydration, which can be exacerbated by excessive sweating. Electrolyte drinks may be beneficial, and it is wise to limit beverages that contribute to dehydration, such as caffeine or alcohol.
Modifying physical activities and diet is a practical approach.
- Exercise in cooler environments, such as an air-conditioned gym.
- Schedule workouts for cooler times of the day, like early morning or late evening.
- Take frequent breaks during any physical exertion to prevent overheating.
- Eat smaller, more frequent meals and avoid spicy foods.
Seeking Medical Evaluation for Heat Sensitivity
Consult a healthcare professional if heat sensitivity is new, severe, or impacting your quality of life. A medical evaluation can help determine if an underlying condition is the cause. A doctor will begin by taking a medical history and performing a physical exam.
During the consultation, the doctor may ask when the symptoms started, if they are worse during exercise, and about any changes in vision or dizziness. Providing a list of your medications helps the doctor make an accurate assessment.
To identify the root cause, the doctor may order tests. Blood tests can check for conditions such as hyperthyroidism by measuring thyroid hormone levels. Other tests may be necessary to diagnose different underlying issues.
Receiving a diagnosis is a key step in management. If an underlying medical condition is found, treating it may alleviate the heat sensitivity. Your healthcare provider can also offer personalized advice to manage symptoms.