Compared to the entirety of human existence, our history of flying in aeroplanes is very short indeed. So what does this fast form of travel do to bodies that have evolved for land-based living? That's what listener Sofia wants to know after working as a flight attendant for over a decade. What effect does working at 35,000 feet have on one's health? How disruptive to your circadian rhythms is hopping across ten time zones in less than 24 hours? What's happening in our stomachs if a crisp packet blows up to the point of popping as the cabin pressure changes? And why do we feel so darn dehydrated when we get off a plane? Host Caroline Steel not only talks to the experts about everything from swollen ankles to what we should eat and drink on planes, she also records her own journey from London to Australia. She does just about everything wrong along the way, but the experts sort her out with some top tips for her next long-haul flight on how to avoid blood clots and even, how to avoid jet lag all together! While in Australia, Caroline also visits a sleep lab where researchers can simulate jet lag to learn how to improve flight safety and the wellbeing of flight attendants and pilots. Join Caroline on her journey as CrowdScience takes to the skies to find out what frequent flyers need to know when it comes cosmic ionising radiation and what we can all do to make that next flight a little more pleasant. Produced by Sam Baker for the BBC World Service. Featuring: Tony Schiemer, Senior Aviation Medical Officer, Royal Australian Air Force Eileen McNeely, Executive Director, SHINE at Harvard T. H. Chan School of Public Health Tracey Sletten, Senior Lecturer, Turner Inst for Brain & Mental Health, Monash University (Photo: Getty Creative # 1432221653)