During an interview with the Mountain Express, Walker said sleep is the single most effective thing that a person can do to reset one’s brain and body health.

“There is not one major physiological system in the body and there is not one principle of principle operation of the mind, from learning memory, attention, creativity and emotional regulation, that is not enhanced by sleep when we get it, or demonstrably impaired when we don’t get enough.”

“As a consequence,” he added. “It is not surprising that many of the diseases that are killing people in the developed world now have significant links, and some of them causal, to a lack of sleep.”

These diseases include depression, anxiety, specific forms of cancer, Alzheimer’s disease, stroke, cardiovascular disease, diabetes, obesity and hypertension, Walker said.

So, how do we get more sleep? Walker provides five guidelines. The first is regularity.

“Go to sleep at the same time and wake up at the first time, whether it is during the week of or on the weekend,” he said.

The second consideration should be room temperature.

“It’s best to draw the core body temperature down by about two to three degrees Fahrenheit,” while sleeping, said Walker. “Aim for a bedroom temperature of around 65 to 67. I know it sounds cold. Wear socks if you must, but cold it must be.”

The third condition that will provide a restful sleep is darkness.

“We are a dark-deprived society in this modern era,” Walker said. “We need darkness to release the hormone melatonin but we are always bathed in electric light or looking at our screens. So in that last hour before bed, dim down the lights in your house and stay away from screens. That will help encourage the release of melatonin.”

The two last concerns are the coffee and alcohol.

“Avoid caffeine after mid-day,” Walker said, if you want a good night’s rest. “It is stimulant and has a half-life of 5-6 hours and a quarter life of 12 hours. Stay away from it after noon. Alcohol fragments your sleep and blocks your dream sleep. Stay away from too many drinks in the evening. Alcohol is a sedative and sedation is not sleep.”

To sleep, perchance to dream, and dreaming is one of the best things about sleep, Walker said.

Dream sleep, or rapid eye movement (REM) sleep, is critical for at least two functions, according to Walker.

“REM sleep seems to provide an overnight therapy,” he said. “It provides a nocturnal soothing bond that takes the sharp edges off difficult experiences that we have so that we come back the next day and feel better about those experiences. It’s not ‘time that heals all wounds’, but it’s time during REM sleep and dreaming that provides emotional convalescence, what I call a form of overnight therapy.”

Walker said there is no medical evidence to support the idea that some dreams are more beneficial than others. He said naps can be good for people who are not struggling with sleep deprivation.

“Even naps as short as 17 minutes can be beneficial,” he said. “But when taken too late in the day they can take the edge off sleepiness. If you are struggling with sleep don’t nap during the day but store up all that sleepiness. But if you are not struggling with sleep, early or mid-afternoon naps are just fine. Try not to make them any longer than 20 minutes.”

Walker has authored more than 100 research publications and is an internationally recognized speaker, having been invited to give talks at the prestigious Royal Institution and Royal Society for the Arts in London, The Smithsonian in the U.S. He has provided on-air discussions on the topic of sleep to the BBC and CBS, as well as popular radio outlets such as the BBC World Service and NPR.

For more information on this year’s virtual Sun Valley Wellness Festival, check sunvalleywellness.org.