Feeling overheated or experiencing heat intolerance can be an unsettling symptom, often prompting concern about serious underlying health issues. While many factors can cause a person to feel unusually hot, the cardiovascular system is central to the body’s cooling process. Understanding the interplay between temperature regulation and heart health is important for recognizing when this feeling might signal a larger problem.
How the Heart Manages Body Temperature
The heart and blood vessels play a key role in maintaining the body’s internal temperature, a process called thermoregulation. When the body heats up, the circulatory system shifts into a cooling mode. To dissipate heat, the brain signals blood vessels, primarily in the skin, to widen (vasodilation). This increases blood flow near the skin’s surface, allowing heat to transfer from the core to the environment.
This redirection of blood flow places a significant demand on the heart. To compensate for the widened vessels and the subsequent drop in blood pressure, the heart must increase its output. It achieves this by pumping faster, ensuring enough blood reaches the muscles and organs while delivering heat to the skin for cooling. The heart’s pumping action is the most important heat-exchange pathway inside the body.
Heart Conditions Linked to Heat Intolerance
When the heart is compromised, it may struggle to meet the increased demands of thermoregulation. In Heart Failure, the heart muscle is weakened and cannot pump enough blood to satisfy both metabolic needs and the cooling requirements of the skin. This reduced pumping capacity prevents the efficient delivery of heat to the surface, causing the core temperature to rise.
Arrhythmias, or irregular heart rhythms, also impair the body’s ability to cool itself effectively by compromising the heart’s efficiency. An irregular or extremely fast heart rate prevents the ventricles from filling completely, resulting in a lower cardiac output insufficient for heat dissipation. Furthermore, Coronary Artery Disease can affect the blood vessels’ ability to dilate properly, limiting the amount of blood shunted to the skin for cooling. This impaired vasodilation increases the risk of heat-related illness during periods of heat stress.
Non-Cardiovascular Causes of Feeling Overheated
While heart conditions are a possible cause, many non-cardiac issues can disrupt the body’s temperature control system. Thyroid disorders, such as hyperthyroidism, speed up the body’s metabolism, generating excess internal heat. Hormonal changes during perimenopause and menopause can also trigger hot flashes and night sweats related to fluctuations in estrogen and progesterone.
Certain medications can interfere with the body’s natural cooling mechanisms. For example, some antidepressants, diuretics, and blood pressure drugs can impair the ability to sweat or affect blood flow regulation, reducing heat tolerance. Additionally, conditions like diabetes can damage blood vessels and nerves, affecting sweat gland function and leading to poor thermoregulation. Stress and anxiety can also trigger a “fight-or-flight” response that increases heart rate and causes a warm, flushed feeling.
When to Consult a Healthcare Professional
If feeling overheated is a new or persistent symptom, or if it interferes with daily life, a consultation with a healthcare professional is warranted to identify the cause. It is particularly important to seek medical attention if the heat intolerance is accompanied by symptoms that suggest a serious underlying issue. These warning signs include:
- Shortness of breath.
- Chest discomfort.
- A rapid or noticeably irregular heartbeat.
- Fainting.
Immediate emergency care is necessary if symptoms progress to signs of heatstroke, such as a very high body temperature, confusion, slurred speech, or loss of consciousness. For less severe, but persistent symptoms like dizziness, nausea, or excessive sweating, a doctor can perform tests to rule out cardiovascular or metabolic causes. If you have a known heart condition, discuss any new or worsening heat-related symptoms with your cardiologist, as your condition or medications may need adjustment.