Our Gemara on Amud Beis Records a practice of helping the Cohen Godol stay awake by placing his feet on the cold marble floor. Indeed, there is a scientific basis for this idea. 

A paper published in the Journal Nature (1999)  https://www.nature.com/articles/43366.epdf?sharing_token=CfJJi5x59F3F2Zdd5qZuctRgN0jAjWel9jnR3ZoTv0McdLoGBqBWDxzYnDuZ89VSsOd_gDIC6yu7SbDYXsM9a63iLB7KHJyKS_Os-MtnAFZReWxUmFpT8xd8_HyFdpoMYMXGDBhQMfwABn_AKxbPCfBP2kwnXAvYtVq0sp6mYLaM7sSTyHdN_WMFbUgVFQsw1eqmONa0veP_6eiudF1KgA%3D%3D&tracking_referrer=www.scienceabc.com  ) 

Explained how warm feet help the body cool down enough to sleep. When researchers artificially warmed feet by placing a warm bottle near the feet, it dilated capillaries, and therefore led to more heat leaving the body. When we go to sleep, and part of preparing to sleep, involves the body’s temperature going down 1 to 2° Celsius. By heating the feet up, more blood is drawn to the feet which have a wide surface area and no hair. Heat leaves the body from the feet more efficiently than from other parts of the body, as the feet act as radiators and it cools down the entire blood temperature. This is also why taking a warm bath or having a warm beverage makes a person sleepy. The blood vessels expand and ultimately more heat radiates out of the body cooling the temperature of the core, which makes you sleepy.

In an opposite manner cooling down the feet will restrict the capillaries, slow down the blood flow to the feet, and causes the core body components to become warmer.  This is why having the Cohen Godol’s feet on the cold floor helps keep him awake.


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Translations Courtesy of Sefaria