Scott Carney is an investigative journalist, anthropologist and author. He reviews how environmental conditioning can improve our health by boosting our metabolic efficiency and improve our immune system.
Most people alive today, climate-controlled comfort has been the experience throughout our life, and we have no reason to believe that exposure to harsh conditions might be beneficial. But, according to Carney, the evidence suggests the human body actually needs those extreme temperature variations.
There are simple things that we can do. To get started just lower the temperature in our homes. Shower like normal with warm water followed by about 1 minute or more of cold water.