What can cause your body temperature to rise?

September 28, 2025 •

4 min read

The body’s average temperature is often cited as 98.6°F (37°C), but it naturally fluctuates throughout the day. Numerous internal and external factors can impact this delicate balance, leading to the question, what can cause your body temperature to rise? This guide provides an in-depth look at the diverse causes, from common infections to environmental stressors and underlying health conditions.

Quick Summary

Beyond common infections like the flu, elevated body temperature can stem from environmental heat, intense exercise, hormonal shifts, chronic stress, or even certain medications. Understanding the different causes, from regulated fevers to unregulated hyperthermia, is crucial for determining the appropriate course of action and recognizing when to seek medical help.

Key Points

Fever is a regulated immune response: When you have a fever, your hypothalamus intentionally raises your body's temperature set-point to help fight an infection, unlike the uncontrolled temperature rise in hyperthermia.
Environmental factors can cause hyperthermia: Conditions like heat exhaustion and heatstroke occur when external heat overwhelms your body's natural cooling mechanisms, posing a serious health risk.
Hormones influence body temperature: Normal fluctuations in temperature occur during the menstrual cycle and pregnancy, while conditions like hyperthyroidism or menopause can cause more significant changes.
Stress can trigger a fever: Emotional distress can lead to a condition known as psychogenic fever, a stress-induced temperature increase that is not caused by infection and is typically resistant to antipyretics.
Medications can affect temperature regulation: Some drugs, including stimulants, antipsychotics, and even certain antibiotics, can interfere with your body's ability to regulate its temperature.
When in doubt, seek medical help: For high or persistent fevers, or when severe symptoms like confusion, a stiff neck, or trouble breathing are present, it is critical to consult a doctor.

The Body's Internal Thermostat: How Temperature Is Regulated

Your body's temperature is meticulously controlled by the hypothalamus, a region in your brain that acts as your internal thermostat. It receives signals from thermoreceptors throughout the body and initiates responses to either generate or dissipate heat to maintain a stable core temperature. When this system is altered, your body temperature can increase. This can happen in two main ways: a regulated increase (fever) or an uncontrolled rise (hyperthermia).

The Common Culprit: Fever Due to Illness

The most familiar reason for a rising body temperature is a fever, which is a key part of your immune system's response to an infection. In response to pathogens like bacteria or viruses, the hypothalamus intentionally raises the body’s temperature set-point. This creates a less hospitable environment for the invading germs, making it harder for them to thrive.

Infections that can cause a fever

Viral Infections: Common culprits include the flu, common cold, COVID-19, and viral gastroenteritis.
Bacterial Infections: These can range from a sinus infection or strep throat to more serious conditions like pneumonia or meningitis.
Autoimmune Diseases: Conditions such as lupus and rheumatoid arthritis cause chronic inflammation, which can result in persistent or recurring fevers.

Environmental Factors and Heat-Related Illnesses

Exposure to extreme heat can overwhelm the body's natural cooling mechanisms, leading to a dangerous and unregulated temperature rise. Unlike a fever, this is not a controlled immune response.

The spectrum of heat-related illness

Heat Exhaustion: This occurs from excessive sweating, which leads to dehydration and overheating. Symptoms include heavy sweating, nausea, dizziness, and weakness.
Heatstroke: A life-threatening condition where the body's temperature control fails completely. Body temperature can rise rapidly to 104°F (40°C) or higher. Symptoms include confusion, dry skin, and a rapid pulse, and it requires immediate emergency medical attention.
Intense Physical Activity: Strenuous exercise, especially in hot or humid conditions, generates significant metabolic heat, raising the core body temperature temporarily. Proper hydration is essential to help the body cool down through sweating.

Hormonal and Physiological Changes

Internal biological processes can also significantly affect your body's thermostat. These fluctuations are often a normal part of life but can sometimes indicate a deeper issue.

The influence of hormones

Menstrual Cycle: Many women experience a slight increase in their basal body temperature after ovulation, during the luteal phase, due to the hormone progesterone.
Pregnancy: Hormonal shifts and increased blood flow during pregnancy can cause a woman to feel warmer than usual.
Menopause: Hot flashes, caused by fluctuating estrogen levels, are a hallmark symptom of perimenopause and menopause, leading to sudden, intense episodes of heat and sweating.
Hyperthyroidism: An overactive thyroid gland produces excess hormones that speed up your metabolism, causing an intolerance to heat and a higher body temperature.

The Impact of Stress and Emotional Factors

Emotional distress can manifest as a physical symptom, including an elevated body temperature. This phenomenon, known as psychogenic fever, is not caused by an infection but by the body's response to stress or anxiety. It is often resistant to typical fever-reducing medications.

How stress affects temperature

Acute Stress: The "fight-or-flight" response triggers a sympathetic nervous system reaction that can temporarily increase body temperature.
Chronic Stress: Long-term psychological strain can cause a persistent, low-grade fever that subsides when the stressor is removed.

Medications and Substance Use

Certain drugs can interfere with the body's ability to regulate its own temperature, either as a direct side effect or by affecting the processes that control heat dissipation.

Medications that can raise body temperature

Stimulants: Illicit drugs like amphetamines and cocaine, as well as some prescribed stimulants, can increase body temperature.
Antipsychotics and Antidepressants: Some psychiatric medications can impair the body's sweating mechanism, making it harder to cool down.
Antibiotics: Certain antibiotics can trigger a fever as a side effect.
Vaccines: It is common to experience a temporary, low-grade fever after receiving certain immunizations as the immune system is activated.

Comparison: Fever vs. Hyperthermia

Understanding the fundamental difference between fever and hyperthermia is essential for proper medical management. The distinction lies in the role of the hypothalamus.


Feature	Fever	Hyperthermia
Thermoregulatory Set-Point	Set-point is raised by the hypothalamus.	Set-point remains normal, but temperature rises uncontrollably.
Primary Cause	Pyrogens (fever-inducing substances) released during infection.	Excessive heat production or inability to dissipate heat effectively.
Body's Response	Initiates heat production (shivering) and heat conservation (vasoconstriction).	Attempts to dissipate heat, but is overwhelmed (e.g., in heatstroke).
Response to Medication	Typically responsive to antipyretics (fever reducers) like ibuprofen.	Often not responsive to antipyretics, as the mechanism is different.
Examples	Common cold, flu, bacterial infections, inflammatory conditions.	Heatstroke, thyroid storm, malignant hyperthermia from anesthesia.

When to Consult a Doctor

While many instances of elevated body temperature are temporary and resolve on their own, certain signs warrant a call to your healthcare provider. Seek immediate medical attention if you or a loved one experiences a fever with severe symptoms, such as confusion, difficulty breathing, a stiff neck, or seizures. For persistent or unexplained fevers that last more than a few days, or if you have an underlying medical condition, it is always best to consult a professional to rule out serious illness. For general health resources, the Centers for Disease Control and Prevention (CDC) is an excellent source of reliable information.

Conclusion

Understanding the various factors that can cause your body temperature to rise is crucial for maintaining good health and knowing when to seek medical help. From the controlled, beneficial process of a fever fighting infection to the dangerous, unregulated state of hyperthermia, the underlying causes are diverse. By paying attention to symptoms, monitoring your body, and understanding the differences between fever and other temperature-elevating factors, you can make informed decisions about your well-being. Always consult a healthcare professional for persistent or severe symptoms.

Frequently Asked Questions

Yes, intense physical activity generates metabolic heat, which causes your body temperature to rise temporarily. Your body then sweats to cool down.

A fever is a regulated increase in body temperature controlled by the hypothalamus in response to an infection. Hyperthermia is an uncontrolled temperature rise caused by external heat or other factors, not a change in the body's set-point.

Yes, significant emotional or psychological stress can cause a condition called psychogenic fever. This is a real, temporary temperature increase and is a physical manifestation of emotional distress.

Yes, several medications, including some antibiotics, psychiatric drugs, and stimulants, can interfere with your body's thermoregulation and cause an elevated temperature.

During the luteal phase of the menstrual cycle, after ovulation, the hormone progesterone causes a slight increase in basal body temperature. This is a normal physiological change.

You should be concerned if a fever is very high (over 103°F or 39.4°C), lasts for more than a few days, or is accompanied by severe symptoms like confusion, a stiff neck, or shortness of breath. Always seek immediate care for heatstroke symptoms.

Yes, heatstroke is a severe and life-threatening heat-related illness where the body's temperature-regulating system fails, causing a dangerous, rapid rise in body temperature.

Yes, dehydration reduces your body's ability to cool itself through sweating, making it more difficult to regulate temperature and increasing the risk of overheating.