Sleep Deprivation: The Burning Question Of Body Temperature

Feeling hot at night can be caused by a variety of factors, including your sleep environment, health conditions, hormones, and even the food and drink you consume before bed. The ideal room temperature for sleep is between 65 and 68 degrees Fahrenheit, and a higher temperature can prevent the body from cooling down. Heavy bedding, thick sleepwear, and warm pillows or mattresses can also contribute to feeling hot. Additionally, pre-sleep activities such as exercise, caffeine consumption, and stressful activities can increase body temperature and make it harder to fall asleep. Hormonal changes, certain medications, and illnesses or infections can also lead to increased body temperature or night sweats. Understanding these factors can help address sleep disturbances and improve overall sleep quality.

High metabolism

Overview

Metabolism is the process by which the body converts food into energy. It involves two types of processes: anabolism, the build-up of molecules, and catabolism, the breakdown of molecules. The metabolic rate is the amount of energy the body burns to maintain itself. During sleep, the metabolic rate and brain temperature are lowered, allowing the body to repair any damage that occurred during the day.

People with a high metabolism may feel hot when they don't sleep due to the interaction between sleep and metabolism. Sleep deprivation can affect the body's ability to regulate temperature, leading to increased body temperature and feelings of warmth.

Sleep Deprivation and Metabolism

Research suggests that sleep deprivation can impact metabolic function and increase the risk of obesity and type 2 diabetes. Sleep-deprived individuals may experience increased appetite, altered glucose metabolism, and decreased energy expenditure, all of which can contribute to weight gain and metabolic issues.

Hormonal Imbalance

Sleep deprivation can disrupt the release of hormones that regulate metabolism, such as insulin, leptin, and ghrelin. Insulin resistance, caused by decreased insulin sensitivity, can lead to elevated blood sugar levels and an increased risk of type 2 diabetes.

Energy Expenditure

Sleep deprivation may also decrease energy expenditure, further contributing to weight gain. This is particularly true for individuals with high metabolisms, as they tend to burn more calories even during sleep.

Appetite Control

Sleep plays a vital role in regulating appetite. Sleep deprivation can disrupt the balance of leptin and ghrelin, leading to increased hunger and a preference for high-carbohydrate and high-calorie foods. This can result in weight gain and metabolic issues.

Obesity and Weight Gain

Chronic sleep deprivation has been linked to an increased body mass index (BMI) and obesity. Studies have shown that individuals who sleep less than 5-6 hours per night tend to have higher BMIs and are at a greater risk of becoming obese.

Skeletal Muscle Metabolism

Sleep loss can also affect the metabolism of skeletal muscle. Insufficient sleep has been shown to decrease muscle protein synthesis and contribute to muscle atrophy. This can further impact overall metabolic function and energy expenditure.

Recommendations

To mitigate the effects of sleep deprivation on metabolism, it is important to prioritize adequate sleep duration and quality. Maintaining a consistent sleep schedule, creating a comfortable sleep environment, and practising good sleep hygiene can help improve sleep and support metabolic health.

Stress

The release of stress hormones during the fight-or-flight response can disrupt your natural sleep cycle and make it harder for your body to regulate its temperature effectively, leading to fluctuations and feelings of being hot. Additionally, when you're feeling anxious or stressed, your body releases cortisol, which increases your heart rate and boosts blood flow, leading to a rise in body temperature.

Practicing deep breathing exercises can help manage feelings of anxiety and stress leading up to bedtime, which may help you feel cooler and sleep better.

Hormone changes

During perimenopause and menopause, estrogen and progesterone levels decline, disrupting body temperature regulation and causing hot flashes and night sweats. This is a very common symptom, affecting around 80% of women going through menopause. The hormonal changes can make it difficult for the body to regulate its core temperature.

Pregnancy can also trigger hormonal changes that result in increased blood circulation and a rise in core body temperature.

Hormonal changes are not exclusive to women. Men can experience sleep disruptions due to hormonal fluctuations as well. Low testosterone levels in men have been linked to night sweats and difficulty regulating sleep temperature.

Additionally, certain medications can affect hormone levels and cause an increase in body temperature. These include hormone-blocking drugs, some diabetes medications, and psychiatric medications such as antidepressants.

Medication side effects

Medication can be a factor in feeling hot while sleeping. This can be caused by the medication itself, or by the effect the medication has on the body's ability to regulate its temperature.

Some medications directly increase body temperature, including:

• Stimulant medications for ADHD, such as methylphenidate, dexamfetamine, and lisdexamfetamine.
• Antipsychotics for mental health conditions, such as clozapine, olanzapine, and quetiapine.
• Levothyroxine, used to treat an under-active thyroid.

Other medications affect the body's ability to cool down by constricting blood vessels and reducing blood flow to the skin. These include:

• Beta-blockers, such as metoprolol, atenolol, and propranolol, used to treat high blood pressure, angina, and heart failure.
• Decongestants, such as pseudoephedrine and phenylephrine.
• Triptans for migraines, such as sumatriptan and zolmitriptan.
• Migraine medications in the triptan family.

Some medications can cause dehydration, which makes the body more susceptible to heat intolerance. Diuretics, such as furosemide, hydrochlorothiazide, acetazolamide, and aldosterone, fall into this category, as do laxatives such as senna extract and bisacodyl.

Medications can also cause a drying effect, reducing the amount of sweat and making it harder to lose heat and regulate body temperature. These include:

• Some antihistamines, such as promethazine, doxylamine, and diphenhydramine.
• Certain antidepressants, such as amitriptyline, clomipramine, and dothiepin.
• Medicines used to treat urinary incontinence, such as oxybutynin and solifenacin.
• Prochlorperazine, used to treat nausea.
• Hyoscine, used to treat stomach cramps and spasms.
• Antipsychotics, such as chlorpromazine, olanzapine, quetiapine, and clozapine.

Finally, some medications can reduce the ability to feel thirsty, leading to a risk of dehydration and feeling hot. Antipsychotics, such as haloperidol and droperidol, can have this effect.

Room temperature

The ideal room temperature for optimal sleep is between 65 and 68 degrees Fahrenheit (19 to 21 degrees Celsius). High temperatures and the presence of warm, humid environments can interfere with the body's ability to cool down.

The human body maintains a consistent temperature during the day, which naturally drops by approximately 1.8 degrees Fahrenheit at night to promote better sleep. However, some people still feel uncomfortably hot while sleeping due to their sleep environment, dietary choices, unique body composition, or other medical reasons.

A person's sleep environment can contribute to them feeling excessively hot during the night. Certain types of sheets and blankets are made to keep you warm by trapping heat. It is best to avoid fabrics like fleece and down that hold body heat, especially during the summer.

Warm pillows and mattresses, such as those made of memory foam, can retain and trap heat, causing you to feel warm all night long. Thick sleepwear can also lead to overheating. Opt for lightweight, breathable fabrics like cotton or linen.

The average adult generates between 75 and 90 watts of heat while sleeping, so sharing a bed with a partner, child, or pet could raise the bed temperature to uncomfortable levels. The more bodies and the smaller the space, the quicker the area will heat up.

Additionally, what you eat and drink before bed can affect your body temperature at night. Heavy and protein-rich meals, sugary energy drinks, and spicy foods can all raise your body temperature. Alcohol can also raise your core body temperature by affecting your blood vessels and disrupting your body's ability to cool itself.

To optimise your sleep environment and help you sleep cooler, try to maintain a cool bedroom and use breathable bedding. Reduce your room temperature before bed to around 65 to 68 degrees Fahrenheit. On cooler evenings, try opening your windows to get a breeze. You can also use a fan or air conditioning to cool the room.

Choose lightweight and breathable fabrics for your bedding and sleepwear. Sleep on bedding that is moisture-wicking and allows for maximum airflow.

It is also important to stay well-hydrated throughout the day before bed, as your body needs water to produce sweat to help cool itself down. Taking a warm bath before bed can also help cool you down faster by increasing blood flow to the surface of the skin and releasing heat into the environment.

Frequently asked questions