Feeling cold or hot during pregnancy: what is normal and how to stay comfortable
Many people feel warmer than usual during pregnancy because metabolism, blood volume and blood flow to the skin all rise. Feeling always cold during pregnancy is less typical and can be linked to anemia, an underactive thyroid, low blood pressure, poor sleep or inactivity. Gentle warming and cooling are fine, but avoid anything that raises core temperature, such as hot tubs and saunas.
Why do you feel hot while pregnant?
Pregnancy turns up the body's heat production. A review of physiological changes in pregnancy reports about a 15% increase in metabolic rate and a 20% increase in oxygen consumption. More fuel burned means more heat to shed.
Circulation changes at the same time. Plasma volume rises by about 50%, mostly by 34 weeks, and cardiac output increases by around 40%. Blood vessels relax, and systemic vascular resistance falls by 25% to 30% to accommodate wider peripheral vessels. More warm blood near the skin is one reason many people feel flushed, sweat more easily and prefer a cooler room.
Carrying extra weight late in pregnancy adds to the effort of ordinary movement. None of this means core temperature is high. It means the body is working harder to keep it where it belongs.
Why am I always cold during pregnancy?
Feeling chilly is less common than feeling warm, but it happens, and it is worth paying attention to because some causes are easy to check and treat.
Anemia is the first to consider. Cleveland Clinic explains that anemia is common in pregnancy, partly because blood volume expands so much, and that low iron, vitamin B12 or folic acid can contribute. Symptoms include extreme tiredness, dizziness or weakness, shortness of breath, a fast heartbeat and pale skin. A complete blood count is usually ordered at an early prenatal visit.
An underactive thyroid is the second. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) lists trouble dealing with cold among the symptoms of hypothyroidism in pregnancy, alongside extreme tiredness, muscle cramps and severe constipation. It affects 2 to 3 out of every 100 pregnancies, and most cases are mild, which is why symptoms can be mistaken for ordinary pregnancy fatigue.
Low blood pressure: Mayo Clinic notes that blood pressure commonly drops in the first 24 weeks of pregnancy as blood vessels expand, which can bring dizziness and fatigue.
Poor sleep and fatigue, which can make you feel colder and less inclined to move.
Sitting still for long periods, especially in air-conditioned offices or drafty rooms.
Skipped meals or nausea that limits how much you eat, leaving less fuel for heat.
When is a temperature change a symptom to report?
Feeling warm in a warm room is expected. A fever, shaking chills, or feeling unusually cold for no clear reason are different, because they can signal an infection or another problem that needs assessment.
Talk to your obstetric clinician promptly if you have a fever, persistent chills, or feel unusually cold, especially with tiredness, dizziness, shortness of breath or a racing heart. Ask how and when they want to be contacted about a fever, since practices give specific instructions. Seek urgent care for signs of heat illness, such as confusion, fainting or a very high body temperature after heat exposure; the Centers for Disease Control and Prevention (CDC) advises seeking medical care immediately for symptoms of heat-related illness.
Is it safe to use a hot tub or sauna while pregnant?
The American College of Obstetricians and Gynecologists (ACOG) advises that it is best not to use saunas and hot tubs early in pregnancy. Its reasoning is that core body temperature rises in them, and that use early in pregnancy, especially for long periods, is associated with birth defects. The CDC similarly notes that a raised internal body temperature in pregnancy has potential links to birth defects and other complications.
The same logic applies to very hot baths, hot yoga and hard exercise in heat. The goal is not to avoid warmth altogether but to avoid anything that pushes core temperature up.
How can you warm up safely during pregnancy?
Safe warming works on heat loss rather than adding intense heat to the core. It is the same approach recommended for anyone who runs cold, with a few pregnancy-specific cautions.
Layer thin, breathable pieces so you can add or remove warmth as your temperature swings through the day.
Keep the torso covered; a warm core helps hands and feet stay warmer.
Wear socks, slippers and a light hat or scarf in cold rooms.
Have warm drinks and regular meals or snacks.
Get up and move for a few minutes each hour if your clinician has not restricted activity.
Use hand warmers or heated clothing on low, over a layer of fabric, and not over the abdomen for long periods.
Is it safe to use a heating pad while pregnant?
A heating pad on a low setting for a short time on sore shoulders or a lower back is a very different exposure from sitting in a hot tub, because it warms a small area of skin rather than the whole body. The main concerns are skin burns and long use directly over the abdomen.
Keep the pad on low, place a layer of fabric between it and your skin, limit the time, and never fall asleep on it. If you are unsure, or if the pain you are treating is new or severe, ask your obstetric clinician before using heat.
How can you stay cool when you feel hot while pregnant?
Because your body is already working harder to shed heat, the CDC notes that pregnancy makes it harder to cool down and raises the risk of dehydration, which reduces your ability to cool yourself by sweating.
Practical steps include drinking fluids regularly, wearing loose, light layers, using fans or air conditioning, taking a lukewarm shower, and scheduling walks or exercise for cooler parts of the day. The CDC also suggests avoiding strenuous activity in heat, resting, and making a heat plan with your doctor before hot weather arrives.
Key takeaways
Feeling warmer in pregnancy is common, driven by a higher metabolic rate, expanded blood volume and more blood flow to the skin.
Feeling always cold during pregnancy can point to anemia, low thyroid or low blood pressure, all of which a clinician can check.
Report fever, persistent chills or feeling unusually cold to your obstetric clinician.
Avoid raising core temperature with hot tubs, saunas and hard exercise in heat.
Warm up with layers, warm drinks and movement, and cool down with fluids, light clothing and air flow.
Frequently asked questions
Is it normal to feel cold in early pregnancy?
Some people do, and fatigue, nausea that limits eating, and lower blood pressure in the first half of pregnancy can all play a part. Feeling cold alongside marked tiredness, dizziness or pale skin can also suggest anemia or a thyroid problem. Mention it at your next prenatal visit, or sooner if it is severe.
Can anemia cause cold hands during pregnancy?
Anemia is common in pregnancy, and feeling cold, tired, dizzy or short of breath are among its reported symptoms. Anemia is diagnosed with a simple blood test that is usually done early in prenatal care. If you have cold hands with these symptoms, ask your clinician whether your blood count should be checked.
Why am I so hot at night while pregnant?
A higher metabolic rate and more blood flow to the skin continue while you sleep, so many people wake up warm or sweaty. Lighter bedding, breathable sleepwear, a cooler bedroom and a fan usually help. Night sweats with fever or chills are different and should be reported to your clinician.
Can I take a warm bath while pregnant?
ACOG's concern is with activities that raise core body temperature, such as hot tubs and saunas. A warm bath that feels comfortable rather than hot is a different exposure, but if you start to feel overheated, dizzy or flushed, get out. Ask your obstetric clinician what bath temperature they consider comfortable for you.
Is it safe to wear a heated vest or use hand warmers while pregnant?
Used on low and over a layer of clothing, these add local warmth rather than raising core temperature. Avoid long periods of heat directly over the abdomen, never sleep with them, and ask your obstetric clinician if you have questions. Our guides to heated vest safety and hand warmer safety cover the details.
Related reading
Sources
Physiological changes in pregnancy, Cardiovascular Journal of Africa via NIH PubMed Central
Can I use a sauna or hot tub early in pregnancy?, American College of Obstetricians and Gynecologists (ACOG)
Heat and Pregnancy, Centers for Disease Control and Prevention (CDC)
Thyroid Disease and Pregnancy, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Anemia During Pregnancy, Cleveland Clinic
Low blood pressure (hypotension): Symptoms and causes, Mayo Clinic
About HEATJAC. HEATJAC is a thermal architecture company founded by an anesthesiologist. We design patented garment systems that capture, conduct and broaden warmth across the body, and we publish this knowledge hub because the science of staying warm should be public. HEATJAC products are not medical devices and are not intended to diagnose, treat, cure or prevent any disease.