It is common for people to feel a sensation of warmth or even experience “hot flashes” in the days leading up to their menstrual period. This feeling is generally a normal physiological response linked to the monthly ovulatory cycle. The body’s subtle temperature fluctuations are directly tied to the shifting levels of reproductive hormones that regulate the menstrual cycle. Rather than indicating an illness or a problem, this warmth is typically a sign that the body has completed ovulation and is progressing toward menstruation.
Hormonal Causes of Temperature Change
The primary driver behind feeling warmer before a period is the release and sustained presence of a hormone called progesterone. Following ovulation, the follicle that released the egg transforms into the corpus luteum, which begins producing large amounts of this hormone. This time frame, known as the luteal phase, is defined by high progesterone levels.
Progesterone acts directly on the brain’s thermoregulation center, the hypothalamus. The hypothalamus functions like the body’s thermostat, setting the baseline temperature. Progesterone elevates this baseline, causing a slight but measurable increase in the body’s core temperature. This effect is why the Basal Body Temperature (BBT) rises immediately after ovulation and remains elevated throughout the luteal phase.
The temperature rise is generally small, typically increasing the core body temperature by about 0.3°C to 0.7°C (or 0.5°F to 1.0°F). While this amount is not considered a true fever, the slight elevation is noticeable enough for many people to feel flushed, warm, or even experience night sweats. If the egg is not fertilized, progesterone levels drop sharply, causing the temperature to fall back down just before or at the start of the period.
When Premenstrual Warmth Becomes a Concern
While a feeling of warmth is a normal part of the premenstrual phase, it is important to distinguish this from a true medical fever. A slight hormonal temperature increase is often perceived as a “feverish” sensation, but a clinical fever is defined as a temperature of 100.4°F (38°C) or higher. Using a thermometer is the best way to determine if the sensation is simply hormonal warmth or a sign of an infection.
Consulting a healthcare provider is advised if the temperature elevation is consistently above the fever threshold or if the warmth is accompanied by other concerning symptoms. Red flags include severe pelvic pain, heavy or unusual bleeding, or symptoms that severely interfere with daily life or sleep. If the sensation of heat persists well into the menstrual period or occurs at times unrelated to the premenstrual phase, it warrants a medical discussion.
These sudden bursts of heat, known as hot flashes, are most often associated with perimenopause, the transition period leading up to menopause. If a person under the age of 40 experiences regular hot flashes before their period, a doctor may want to rule out conditions like Primary Ovarian Insufficiency (POI) or a thyroid disorder, such as hyperthyroidism, which can also affect the body’s temperature regulation. Anxiety and stress can also trigger physical symptoms that mimic hot flashes, including flushed skin and an increased heart rate.
Practical Strategies for Cooling
Since premenstrual warmth is a predictable physiological event, several non-medical strategies can help manage the discomfort. Focusing on hydration is beneficial, as drinking cool water helps the body regulate its temperature and prevents dehydration, which can worsen feelings of warmth. Sipping on cold, non-caffeinated beverages can provide immediate relief.
Adjusting clothing and environment can also make a noticeable difference. Opting for loose-fitting garments made from breathable materials like cotton or linen allows for better airflow and prevents heat from being trapped against the skin. Layering clothing is helpful so that items can be easily removed when a wave of heat strikes.
Environmental control, such as using a fan or lowering the thermostat in the bedroom, is particularly useful for managing night sweats. Lifestyle adjustments can also minimize triggers. Avoiding spicy foods, excessive alcohol, and high amounts of caffeine during the luteal phase may reduce the frequency and intensity of hot flashes.