I am interested in learning more about the skin as an organ, specifically the brain/body connection. Do the chemicals we add in the form of lotions, perfumes, epsom salt baths, etc. permeate the barrier and enter the bloodstream/muscles? Are there any nutrients better "ingested" through the skin? Does the rise in skin cancer rates relate to sunscreen usage or the extra exposure to the sun based on the brain's inability to detect the harmful rays due to sunscreen usage? Why do we have freckles, moles, acne, wrinkles, sunspots? Could skin stressors (like cold plunging and sauna) be just as beneficial on a seasonal basis? In other words, could one expose oneself to the cold more in the winter, but switch to heat stressing in the summer and achieve the same brain/body "struggle" benefits?