Pregnancy and Body Temperature Fluctuations: What's Normal & When to Worry

Body temperature changes aren't just about hot flashes. Your body is adapting to a new state.

From the moment pregnancy begins, your body enters a new metabolic state. You might find yourself tossing the blanket off at night, sweating through a T-shirt, or reaching for a shawl even on a warm day. These temperature changes can feel confusing, especially when they come without warning. But most of the time, they’re normal.

Increased progesterone levels, elevated metabolism, and higher blood volume can all raise your core temperature slightly. But not all temperature shifts are harmless. It's important to learn what’s typical, what might require medical attention, and how to manage the discomforts that come with these fluctuations.

What Causes Body Temperature Fluctuations in Pregnancy?

Pregnancy triggers complex physiological shifts that affect thermoregulation, the body’s ability to maintain a stable temperature.

Hormonal Changes: Progesterone, the hormone that supports early pregnancy, also acts on the hypothalamus, the brain’s thermostat, raising your basal body temperature (BBT) by about 0.5°C from ovulation onward.
Increased Blood Volume: Your blood volume increases by nearly 40%–50%, boosting circulation and heat production. This can leave you feeling warmer, especially in the face and chest areas.
Faster Metabolism: The increased energy demands of pregnancy raise your resting metabolic rate, producing more internal heat even when you're at rest.
Sweat Gland Activation: You may sweat more to compensate for internal heat. This is the body's natural way of cooling down.
Environmental Sensitivity: Pregnant women often become more sensitive to heat or cold, especially in tropical or humid climates like many parts of India.

What's Normal and What’s Not?

Knowing the difference between a normal rise in body heat and a potential red flag is essential.

Normal Temperature Ranges in Pregnancy

Basal body temperature can stay elevated at 37.0–37.2°C (98.6–99°F)
You may feel flushed or sweat more, especially at night
Occasional chills or feeling cold is also common due to hormone fluctuations

When to Worry

Persistent fever above 38°C (100.4°F): Could indicate infection such as flu, urinary tract infection, or COVID-19
Chills with high fever: May suggest an underlying bacterial or viral illness
Fluctuating fevers with rashes or joint pain: Get tested for dengue, malaria, or typhoid, especially during the monsoon season
Temperature drops below 36°C (96.8°F): Though rare, it may signal a complication such as hypothyroidism or shock

Always contact your doctor if your temperature rises to 38°C and stays high for more than 24 hours, or if fever is accompanied by abdominal pain, decreased fetal movement, or discharge.

Risk Factors That Make You More Susceptible

Certain conditions can make body temperature fluctuations more extreme:

Anaemia – Reduced oxygen-carrying capacity can heighten fatigue and make you feel cold or weak
Thyroid disorders – Both hypothyroidism and hyperthyroidism can affect temperature regulation
Infections – UTIs, respiratory illnesses, and other infections are more common during pregnancy
Dehydration – Can impair your body’s cooling mechanism, especially in hot weather
Gestational diabetes – Affects metabolism and thermoregulation

How to Check and Monitor Your Temperature

While it’s common to feel off-balance, having a home thermometer helps track your symptoms.

Digital Thermometers – Use underarm or oral thermometers to track temperature accurately
Track over time – Don’t rely on a single reading. Chart any pattern over 24–48 hours
Combine with symptoms – Note if you're experiencing fatigue, chills, backache, or burning while urinating

Managing Body Temperature Swings Safely

For Feeling Too Warm

Wear breathable fabrics like cotton or bamboo
Use ceiling fans and keep rooms well-ventilated
Stay hydrated—aim for 8–10 glasses of water daily
Avoid caffeine and spicy food that may raise heat

For Feeling Too Cold

Add light layers that are easy to remove
Warm soups and herbal teas (like tulsi or ginger) can help
Check for underlying anaemia or thyroid issues
Avoid cold drinks if they worsen chills

If You Have a Fever

Rest, hydrate, and take antipyretics only if advised by your doctor
Avoid self-medicating with antibiotics or herbal remedies
Seek medical attention if the fever persists or worsens

Emotional and Practical Support

Fluctuating temperatures can also impact your emotional well-being. You might feel irritable, fatigued, or out of control. Support yourself by:

Taking short breaks to cool off or warm up, depending on symptoms, is necessary.
Communicating with your care team about how you’re feeling physically and emotionally is crucial as well.
Asking for help, whether it’s a fan, a thermos of hot water, or reassurance, small comforts go a long way.
Use Ayurvedic care cautiously. Herbs like Shatavari are cooling and safe when supervised; heating herbs like ashwagandha should be avoided unless prescribed.

Body temperature changes are part of your body’s complex adaptation to pregnancy. Most are harmless, but it’s important to watch for signs that indicate something more serious. Trust your instincts, track your symptoms, and don’t hesitate to reach out for medical support. With the right knowledge and care, you can stay safe, informed, and more comfortable through every trimester.