Just chilling out

摘要

Early last year we travelled to the icy mountains of Poland as part of an unusual experiment. A group of volunteers that we had recruited spent the next four days immersing themselves in freezing-cold water, lying in snow or hiking up a mountain wearing just shorts in temperatures as low as -27 ℃. We were hoping these volunteers might shed new light on the workings of the immune system. Our immune system is vital for protection against invaders such as bacteria and viruses, and without it we would be quickly overcome. But there is another side to this story: many conditions are caused by the immune system kicking in when it shouldn't, attacking components of our bodies. These autoimmune disorders include rheumatoid arthritis, multiple sclerosis and type 1 diabetes, with more than $100 billion spent annually on treatment for these conditions in the US alone. If there was a way to control our immune reactions without drugs, the benefits would be huge. Even better, what if we could consciously control our immune system?