Why You're So Hot All the Time During Pregnancy and Postpartum

You are not imagining it. The heat is real.

Whether you are deep in your third trimester or a few weeks postpartum, feeling constantly warm, flushed, and uncomfortably sweaty is one of the least talked-about realities of this season of life.

It is also one of the most universal.

Here is the science behind what is happening, and why your body is working exactly as it should.

1. Your Blood Volume Increases by Nearly 50% During Pregnancy

This is one of the most staggering facts about pregnancy that most mums never hear. 

According to the American College of Obstetricians and Gynecologists, blood volume increases by approximately 40 to 50 percent during pregnancy to support the placenta and growing baby.

More blood moving through your body means more heat generated. Your heart is working harder. Your circulation is ramped up. Your skin becomes a natural radiator, releasing that extra warmth outward.

That permanent flush on your cheeks is not a glow in the marketing sense.

It is your body doing serious work.

2. Your Metabolic Rate Rises Significantly

Your body is building a human being. Naturally, that costs energy, and energy production creates heat.

Research published in the American Journal of Clinical Nutrition shows that the metabolic rate increases progressively through pregnancy, peaking in the third trimester.

Think of it like your internal engine running at a higher speed than usual. The by-product of that extra effort is heat, and lots of it. Even at rest, your body is burning more energy than it ever has before.

3. Postpartum Hormones Trigger a Sudden Temperature Reset

After birth, oestrogen and progesterone levels drop sharply.

These hormones had been elevated throughout pregnancy, partly responsible for that elevated warmth you felt.

According to the Mayo Clinic, this sudden hormonal shift causes the hypothalamus, the part of your brain that regulates body temperature, to temporarily misread your core temperature.

The result is hot flushes, night sweats, and that persistently overheated feeling in the early postpartum weeks. Most mums experience this most intensely in the first two to six weeks after birth.

4. Your Bra and Fabric Choices Matter More Than You Think

When your body is already producing excess heat, wearing synthetic fabrics or an ill-fitting bra makes everything worse.

Synthetic materials trap heat and moisture against the skin. For nursing mums, a bra that sits too tight or in the wrong position also adds friction and pressure to already sensitive breast tissue.

Natural fibres like cotton allow airflow, wick moisture more effectively, and feel significantly cooler against the skin.

It is a small change with a surprisingly large impact on daily comfort.

Lovemère mom wearing Holiday Triangle Bra.

5. Practical Things That Actually Help

You cannot switch off the hormones, but you can work with them. A few things consistently make a difference.

Hydration is more important than most people realise.

According to the NHS, breastfeeding mums need extra fluid daily to support milk production, and dehydration makes heat sensitivity worse.

Keep water nearby during every feed.

Choose loose, breathable layers you can remove easily. Sleep with lighter bedding. Time outdoor activity for early morning or evening when heat is lower.

And do not underestimate the difference a breathable bra makes at night, when night sweats are often at their peak.

When to Mention It to Your Doctor

For most mums, feeling hot and sweaty during pregnancy and postpartum is entirely normal and resolves on its own.

That said, it is worth mentioning to your doctor if the hot flushes are accompanied by a high temperature, heart palpitations, or feel extreme rather than uncomfortable. In rare cases, thyroid changes postpartum can amplify heat sensitivity and are worth ruling out.

The Bottom Line

Your body has increased its blood volume, boosted its metabolism, and is now recalibrating its entire hormonal system.

Feeling hot is not a malfunction. It is evidence of how hard you are working.

Give yourself some grace in this season. Choose fabrics that breathe, stay hydrated, and know that this phase does pass. Most mums find the intensity of postpartum heat sensitivity settles considerably by six to eight weeks.

Learn More:

Research sources: American College of Obstetricians and Gynecologists (ACOG), Mayo Clinic, NHS (National Health Service), American Journal of Clinical Nutrition

Additional resources: Cleveland Clinic Postpartum Care Guide, NHS Pregnancy and Postnatal Health

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