Thermoregulation and sleep: Achieving the body’s optimum temperature

It’s 3 a.m., you're wide awake, and counting the hours until you have to get out of bed. Your mind is racing, contemplating, tossing, turning. You’re hot and cold at the same time. You have a million and one things to do, but you just want to go back to sleep.

We’ve all been there, and it is the worst. Some of us just get up, pour a cup o’ joe, and tackle the day … only to be exhausted and reaching for more fuel by noon. Others stare at the ceiling, trying to will themselves back to dreamland (even if it’s only for a few precious hours).

Not only is sleep important for our well-being, but it is essential to get good quality sleep. If you’re tossing and turning throughout the night, one problem may be your body temperature. Research provides sufficient evidence that breast cancer patients are frequently deficient in achieving thermal comfort. In essence, they feel excessively hot or cold. [1]

So, if we spend one-quarter to one-third of our lives sleeping, shouldn’t we try to do it as peacefully and comfortably as possible? After all, your circadian rhythm – your 24-hour “internal clock” – knows when it’s time to get up and when it’s time to go to sleep. It’s just another example of listening to your body.

Let’s take a look at how temperature, the circadian rhythm, and cancer affects sleep patterns:

Why your body temperature matters 

Sleep looks like a passive state of being. However, many functions – those that promote well-being and are closely linked to our quality of life – do optimum work while the body is resting.

Are you the type who turns down the thermostat before bed to arctic temperatures with your fan blasting on high? Or are you the type who has not one, not two, but three blankets to keep you cozy?

Commonly people go to bed clothed and under their bedding, in turn, causing heat exposure. The research concludes that heat exposure can increase wakefulness during sleep stages. [2]

The thermal environment is a crucial determinant of sleep because thermoregulation is strongly linked to the mechanism that regulates sleep. Excessively high or low ambient temperature may affect sleep even in healthy humans without insomnia.

Furthermore, disturbed nocturnal sleep affects all aspects of daily life, not only daytime activities. It also is related to various adverse health effects, such as obesity, quality of life, and even mortality. These findings indicate that maintaining a comfortable thermal sleep environment is vital for sleep maintenance as well as daytime activities and health status. [3]

The importance of circadian rhythm

The hypothalamus, a portion of your brain, controls your circadian rhythm. Environmental components – temperature and light – are among the factors that control signaling to the hypothalamus that it is time to wake up or to go to bed. [4]

There seems to be a connection between melatonin suppression and the context of the circadian rhythm. [5] The pineal gland is a small pea-shaped gland found in your brain that regulates hormones, including melatonin, which plays a fundamental role in regulating circadian rhythm.

Once the sun goes down, the pineal gland is turned on and produces melatonin. As the melatonin in your blood rises, your body is signaled that it’s time to go to sleep. Research shows melatonin also has a significant impact on the immune system (immune cell trafficking and cytokine production), thus helping it manage and fight malignancies. [6]

A 2014 study found that a lack of sleep can cause cellular damage, DNA replication errors, and metabolic abnormalities. This provides a possible link between sleep loss and increased disease and cancer risk. [7] We know that cancer cells are abnormal and damaged, and are incapable of adequately controlling their growth and replication. Thus, taking care of our cellular health – including quality sleep – is essential.

Research on chronic irregular sleep is evident. Disrupted sleep has strong links to increased risk of breast, prostate, and thyroid cancers. [8-10] Changing your daily habits to make sure you are getting a sufficient amount of sleep is a short-term issue; you can efficiently resolve this to lower your cancer risks.

How sleep influences a cancer patient

Sleep is complicated, but when you add cancer to the mix, things get more involved.

Dr. Lois Krahn, who has been conducting research and clinical practice as a sleep medicine specialist for more than 20 years, estimates 75% of people with cancer have insomnia or another sleep disorder. A faculty member at the Mayo Clinic in Phoenix, Arizona, Dr. Krahn also notes 80% of cancer patients have fatigue.

“So many things are happening while we're asleep,” says Amanda Phipps, an epidemiologist and researcher at Fred Hutchinson Cancer Research Center in Seattle. “It's a time when we most efficiently repair DNA damage. The body is also doing things like controlling the growth of cells, turning on certain genes, and switching off others, and promoting the immune system. [11]

“Sleep is a time for repair and restoration of our bodies, but it's more than just that,” Phipps adds. “It's also building up our immune systems so we can better protect ourselves during the day.”

Technology, tools to help you sleep better

Technology has come a long way, and it’s incredible to see all the tools available to help our everyday lives. Here are some great tools that may help you catch up on sleep. 

ChiliPAD: Ideally, our body’s core temperature should drop with our sleep-wake schedule. Many of us suffice with cranking down the thermostat or using fans. The chiliPAD sleep system consists of a hydro-powered mattress pad, thermal regulating control unit(s), and a remote, making it perfect for one or two sleepers. This system utilizes water and operates between 55-115°F (13-46°C), helping encourage quality, restorative sleep. [12] 

Weighted Blankets: Weighted blankets typically weigh between 5 and 30 pounds and mimic deep pressure stimulation, a therapeutic pressure technique. Anxiety can wreak havoc on your sleep. The research was done on the safety and effectiveness of 30-pound weighted blankets on 32 adults. The results revealed 63% reported lower anxiety, and 78% preferred the blanket as a calming modality. [13]

Ebb sleep with precision cool technology: Research shows that cooling the forehead (interface for your cerebral cortex) may help with insomnia. A study tested cerebral thermal transfer using a cap filled with tubes of circulating water on 12 patients with primary insomnia and 12 healthy patients. The patients with insomnia were able to sleep as well as healthy patients using the therapy. [14] Ebb sleep is a triple-layered headband that allows for ideal-temperature cooling to hit just the right spots of your head, to calm and enable deep sleep. 

There also are habits that can impact your sleep routine:

• Put away your phone and turn off the TV. It’s easier said than done, but try to avoid electronic devices that put off a bright light at least 1 hour before bed. (Also, use nighttime settings – a dimmer lighter – on your devices.)
• Do not share the bed with the family pet. Their sleep rhythms differ from ours, and when Fido is running in his dreams, it wakes you up. This can be very disruptive to your internal sleep clock, especially if this is happening daily.
• Caffeine should be avoided at least 6 hours before bed. 
• Alcohol is a known carcinogen, but if you are going to have that nightcap, try to do it at least 3 hours before bed. Alcohol can suppress melatonin and disrupt your circadian rhythm. [15]
• Late-night snacking and meals should be finished 2-3 hours before bed. That gives your digestive tract plenty of time to break down your food, in turn avoiding late-night heartburn and indigestion that can impact your sleep.

Conclusion

Sleep is essential to our overall health. You can feel it when you don't get enough sleep; you become groggy, tired, and irritable. That is just our body's way of saying, “Hey, I need sleep!”

Life stressors, including cancer and even cancer treatments, might be a contributing factor to why you are not getting enough shut-eye.

If you think you may have insomnia or another sleep disorder, it is essential to talk with your physician; there are options that can help.

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