There are several possible reasons why you may feel hot while sleeping. It could be related to your body composition, your bedding, or the temperature of your room. You may also sweat more than usual. If you have a fever, your body will naturally generate more heat as well.
1. Room Temperature and Humidity
If you feel too hot at night, your room temperature may be too high. Prolonged exposure to heat during the night can increase wakefulness and reduce both slow-wave sleep and REM sleep.
Humidity can intensify the effects of heat by preventing sweat from evaporating properly.
2. Sleepwear and Bedding
Just like insulation in your home, your bedding acts as a form of insulation. Thicker bedding retains more heat than lighter options, and wearing heavy sleepwear can also lead to overheating.
Different materials have varying heat retention properties, which can affect your sleep quality.
At temperatures of 63°F and 72°F (17°C and 22°C), studies have examined the effects of cotton and wool sleepwear, as well as polyester and wool bedding, on sleep quality.
At 63°F (17°C), wool sleepwear was found to promote better sleep compared to cotton, although cotton resulted in deeper sleep at 72°F (22°C).
Researchers found no significant difference in sleep onset or overall sleep quality between polyester and wool bedding at either temperature.
3. Pre-Sleep Activities
The activities you engage in before going to bed can increase your body temperature, making it harder to fall asleep.
Exercise: According to a modest 2018 literature review, evening exercise does not negatively affect sleep and may even have the opposite effect. However, falling asleep can be more difficult if intense physical activity is completed within an hour before bedtime.
Caffeine: Consuming caffeine close to bedtime has been shown to make it harder to fall asleep. A small 2014 study found that caffeine is associated with higher body temperature and increased mental alertness.
Stressful activities: Your blood vessels constrict when you are stressed. According to a 2015 animal study, this process lowers your skin temperature while increasing your core body temperature.
Sex: Sexual activity can help you sleep better by releasing chemicals that promote relaxation. On the other hand, vigorous sexual activity that raises your heart rate may have effects similar to exercise.
Is sleeping naked beneficial? Read this guide: Is Sleeping Naked Better?
4. Who You Sleep With
Your combined body heat can increase the temperature under the covers and in your room if you sleep with another person or with pets.
Due to metabolism, the body continuously produces heat. This heat builds up more quickly when more people share a smaller space.
The average human body temperature is about 98.6°F (37°C). If the room temperature is high, your body may absorb additional heat, making it harder to cool down
5. Prescription Medications
Many medications can increase your body temperature or interfere with your body’s ability to regulate heat.
6. Hormones
Hormonal imbalances can cause night sweats or hot flashes.
Premenstrual syndrome (PMS) can lead to night sweats in many women due to changes in estrogen and progesterone levels.
Menopause is characterized by night sweats and hot flashes, two of its most common symptoms. These occur due to a decrease in estrogen and other hormonal changes that are not yet fully understood.
Pregnancy-related hormonal changes can increase blood flow and raise body temperature.
Hyperthyroidism and obstructive sleep apnea (which affects multiple hormones) are two possible causes of night sweating.
If you’re concerned about sleep apnea, read this guide: Can Sleep Apnea Kill You?
7. Infections and Illness
Various conditions can lead to an increase in body temperature or cause night sweats. The following infectious diseases may raise body temperature:
Other bacterial infections include:
- Influenza (flu)
- Strep throat
- Pneumonia
- Pulmonary tuberculosis
- The common cold
Other factors that may cause you to feel excessively hot at night include:
- Cancer
- Coronary artery disease (CAD)
- Hyperhidrosis (excessive sweating)
- Hyperthyroidism
- Chronic stress
How Does Body Temperature Affect Your Sleep?
Over a 24-hour period, your body temperature follows a natural cycle. Typically, your body temperature:
- Drops in the evening
- Rises in the morning
- Peaks later in the day
If your body temperature does not decrease in the evening, it can negatively affect your sleep.
According to research conducted in both humans and animals, people tend to naturally choose their bedtime during the period when their body temperature is dropping the most.
When Should You Be Concerned About Night Sweats?
Occasional night sweats are usually not a cause for concern. However, if you frequently experience night sweats along with other symptoms, you should consult a doctor.
Additional symptoms to watch for include:
- Chills
- Fever
- Unexplained weight loss
- Body aches
If you often experience night sweats, it can be helpful to keep a journal tracking how frequently they occur and any accompanying symptoms. This can help you and your doctor identify the underlying cause.
Solutions for Feeling Too Hot at Night
Here are some suggestions to help prevent overheating at night:
Room Temperature
- Lower the temperature.
- Open a window to improve airflow.
- Use a dehumidifier to reduce humidity.
- Use a fan or air conditioning to keep the room cool.
- Place your mattress closer to the ground to stay cooler.
- Take a cool shower before going to bed.
Bedding
- Reduce the number of blankets you use.
- Choose lightweight, breathable fabrics.
Pre-Bedtime Habits
- Finish exercising at least one hour before bedtime.
- Avoid consuming caffeine in the late afternoon or evening.
- Stay away from stressful activities before sleep.
- Avoid intense sexual activity before bedtime (gentle activity may actually improve sleep quality).
Sleeping With Others or Pets
If you share a bed with someone, consider using separate blankets.
Open a window or keep the door open if possible to improve airflow.
Medications
Contact your doctor to check whether your medications can be adjusted.
Ask your doctor about the best treatment options for your specific hormonal issues.
If you are sick or have an infection, try to treat the underlying cause.
Conclusion
Although there are many ways to reduce night sweats, you should speak with a doctor to determine whether it may be a medical issue. If you have any underlying health concerns, you may need to be evaluated for a sweating disorder.
You can also monitor your body temperature and make adjustments using bedding or cooling products.
Repopny hopes this article has helped answer your questions.