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Waking up cold is no fun, especially when you're left tossing and turning, desperately trying to drift back off. Let’s find out why it happens and how to stay cosy for uninterrupted snoozing.
6 Min Read | By Jessica Kadel
Last Modified 30 September 2025 First Added 2 January 2020
At some point, we’ve all woken up shivering and clutching the duvet in the middle of the night. This midnight chill is actually your body’s clever way of helping you sleep – though it might not feel particularly helpful at 3 am! Understanding why this happens can help you work with your body’s natural rhythms and create the perfect sleep environment.
Your body is designed to cool down while you sleep, but sometimes this natural temperature drop can leave you feeling chilly at night. Here are some natural reasons you might wake up cold:
When you sleep, your core body temperature drops by 1-2 °C to align with your circadian rhythm. This dip is completely normal and signals to your brain that you’re ready to sleep. This might not seem like much, but it can sometimes make you feel chilly at night and even wake you up.
Your core temperature drops until about halfway through a sleep cycle, when it reaches its minimum. The timing of this varies; in fact, a sleep study found that morning people reached their lowest temperature after 3.5 hours, while night owls took longer at 6.01 hours.
In short, your body cools as part of its natural sleep cycle, but if the drop is too sharp, it can wake you up.
At night, your metabolic rate can drop by up to 15%, conserving energy and making you feel cooler. Your body prioritises minimal energy use for heat production, freeing up resources to restore and reset your brain for the next day.
Your bedroom setup and clothing play a huge role in how warm or cold you feel overnight. Chances are, if you’re getting chilly in bed, it may be time to bundle up. Let’s explore the environmental causes of waking up cold.
If your thermostat is set low, or if you sleep near drafts or poorly insulated windows, your bedroom could get uncomfortably chilly. Aim for 16–20 °C for the most comfortable sleep. Learn more in our guide: What’s the best temperature for sleep?
Some duvets aren’t very effective at retaining heat. Choosing the right bedding for colder weather, such as one made from flannel or fleece, can make a big difference. Layering your blankets can also help you stay warm and cosy while you rest.
Many people accidentally kick off blankets during the night. If this happens to you, a heated blanket underneath your covers can help maintain warmth all night.
Sleeping naked or in very light clothing can leave you feeling cold. Thermal pyjamas or layered sleepwear are more effective at keeping your body heat consistent. Learn more about what to wear to bed.
Even if the rest of your body feels perfectly toasty, cold feet can be the one thing keeping you from your slumber. Poor circulation or sleeping with bare feet can make this worse, so go ahead and embrace those bed socks! They’ll help you stay warm and cosy all night long.
Sometimes, feeling cold at night isn’t just about your bedroom or bedding; it can be linked to your body, habits, or health:
Do you experience cold hands and feet? Reduced blood flow and poor circulation can cause icy cold sensations. This can be linked to sitting still for long periods, anxiety, low iron, or other health conditions.
Worrying about future plans or overthinking how your day went can impact your ability to fall asleep and affect your overall body temperature. Stress or anxiety can cause blood vessels to constrict, limiting blood flow and making you feel colder.
Poor nutrition and low sugar levels can weaken your body’s ability to regulate temperature. This is because your body doesn’t have enough energy to produce and retain heat. As well, deficiencies in iron and vitamin B12, found in greens, chicken, eggs, and fish, can leave you feeling cold and fatigued.
Body fat acts as natural insulation. Less fat means your body loses heat faster, making it harder to stay warm at night.
Low hydration slows your metabolism, making it harder for your body to produce heat. To stay hydrated before bedtime, why not try one of our drinks to help you sleep?
Chronic sleep deprivation disrupts your body’s temperature regulation. Without sufficient restorative sleep, your core temperature can drop more than usual, leaving you colder at night.
Several other medical conditions can cause you to feel cold more often, especially when your core body temperature drops at night. These include:
If you think you may be affected by any of the above conditions, talk to your doctor about the best treatment options.
Some prescriptions, like beta-blockers and certain antidepressants, can affect your body temperature. Beta-blockers slow your heart rate, lowering blood flow to your hands and feet, making you more sensitive to the cold, whereas antidepressants slow down your metabolism.
Other medications may affect your thyroid function or hormonal balance as a side effect which can then impact body temperature regulation. These combined with environmental factors can make you feel chillier at night.
If you’re tired of shivering or waking up feeling cold, a few simple tweaks can help:
Vitamin B12 and iron deficiencies are two common reasons you might feel colder than usual. B12 can be found in chicken, eggs, and fish, while iron is best sourced from green vegetables such as spinach, beans, and broccoli. According to Health, regular intake of these nutrients can help you stay warm and prevent issues like hypothyroidism and anaemia.
Dr Holly Phillips, author of The Exhaustion Breakthrough, says, “Iron is a key mineral that helps your red blood cells carry oxygen throughout your body, bringing heat and other nutrients to every cell in your system.”
If you’re not just waking up cold but shivering, it could be a sign of an underlying health condition. These can include:
If you’re always cold despite adjusting your environment and lifestyle, or if chills come with other symptoms like fatigue, dizziness, fever, or sweating, it’s best to consult your doctor. Persistent night chills may signal an underlying medical issue, such as thyroid disorders, anaemia, infections, or circulatory problems.
Feeling cold at night is usually normal and can be caused by body temperature drops, your environment, or lifestyle factors. Simple changes, like adjusting your bedroom, layering bedding, wearing warm sleepwear, staying hydrated, and eating well, can all keep you cosy and help improve your sleep. If chills persist despite these steps, consult a doctor to check for underlying medical conditions.
See all articles by Jessica Kadel
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