Postpartum Thermoregulation: Why You’re Sweating, Shivering, or Freezing
Woman sweating
You’ve just had a baby, your body’s been through a monumental event, and suddenly you’re waking up drenched in sweat — or shivering under three blankets. These unexpected postpartum temperature shifts are more common than you might think.
This experience is linked to postpartum thermoregulation — the way your body adjusts its internal temperature after childbirth. It’s real, it’s physiological, and it can be unsettling if you don’t know what’s going on.
What Is Thermoregulation and Why Does It Matter Post-Birth?
Thermoregulation is your body’s way of maintaining a stable internal temperature. It’s controlled by the hypothalamus, a part of your brain that acts like a thermostat, responding to internal signals (like hormone levels and inflammation) and external factors (like room temperature or skin exposure).
During the postpartum period, your body is recalibrating — hormonally, immunologically, and metabolically — and this can throw your thermostat off temporarily.
Why You Might Be Sweating After Birth
Night sweats and increased sweating are especially common in the first 1–2 weeks postpartum. Here's why:
🧪 Hormonal Shifts: After birth, levels of oestrogen and progesterone plummet. These hormones previously regulated your fluid retention. Their sudden drop signals your body to release excess water — and sweating is one way it does that.
💧 Fluid Loss After Birth: If you received IV fluids during labour (especially with an epidural or caesarean ), your body now has to offload that extra volume. Sweating and increased urination help you shed it.
🌡️ Metabolic Adjustment: Your basal metabolic rate remains high in the early postpartum period, contributing to increased heat production — especially during breastfeeding, which spikes oxytocin and prolactin.
Why You Might Feel Cold or Shivery
Chills and shivers — sometimes even violent, full-body shaking — can happen immediately after birth or days later. These are normal responses to:
🧠 Adrenaline Rush: After labour, your body releases adrenaline to help with blood loss, delivery of the placenta, and alertness. The “comedown” from this can cause you to feel shaky or cold.
🔄 Thermostatic Reset: Your hypothalamus may briefly “misfire” during this transitional period, creating temporary mismatches between body temperature and environmental conditions.
💉 Blood Loss & Anaemia: Significant blood loss can lead to postpartum anaemia, which is associated with feeling cold, tired, and weak. If chills persist beyond a few days, especially with dizziness or fatigue, ask your midwife or GP about checking your iron levels.
How Breastfeeding Affects Your Temperature
When you breastfeed, your body increases blood flow to the chest and breasts, sometimes raising your local skin temperature by 1–2°C. This warmth helps keep your baby cosy — nature’s built-in heater. But it can also make you feel overheated or flushed, especially in the early weeks.
When to Be Concerned: Signs of Infection
While most temperature swings are completely normal, it’s important to stay alert to signs of infection. Call your midwife or doctor if you experience:
A persistent fever above 38°C (100.4°F)
Chills with flu-like symptoms
Offensive-smelling lochia (postpartum bleeding)
Pain, redness, or swelling in your breasts (signs of mastitis)
How to Stay Comfortable During Postpartum Temperature Swings
🛏️ Dress in breathable layers you can peel off or add as needed
🧴 Stay hydrated, especially if you’re sweating and breastfeeding
🌬️ Use a fan or open window at night to regulate your sleep environment. Remember postnatal wards on hospitals are often rather warm anyway.
🧦 Keep warm socks or a dressing gown nearby for sudden chills
🧘♀️ Practice calming breathwork to soothe post-adrenaline shakes
Conclusion: Trust Your Body — It’s Resetting
Postpartum thermoregulation may feel strange, but it’s a powerful sign of your body recalibrating after birth. These sweats, shivers, and chills are part of the process — not a sign that something’s wrong.
By understanding what’s happening inside, you can feel more prepared, less alarmed, and better supported through the fourth trimester.
