With Fun Taiwan in its 10th season and a recent expansion into Fun Asia, travel host Janet Hsieh has been keeping busy. She did, however, manage to squeeze in a trip to the United States that yielded Fun USA (TLC, Fridays at 10pm), exploring the Pacific Northwest states of Oregon and Washington in a two-episode series. Short as it is, Hsieh's trip is action packed. In Oregon, she plays bridesmaid at Portland's famous Voodoo Doughnuts and puts on a pair of roller-skates to join the tough-looking roller derby girls in their own version of Whip It! She also visits Willamette Valley for a spot of biodynamic wine-making, before finding herself in the picturesque sports town of Hood River, to experience the thrills of kite-boarding. In Washington state, Hsieh romps around with friendly wildlife and samples local delicacies before going sleepless in Seattle with a gang of striptease artists. She even has time to hang out with her dad, before heading back to Taiwan in time to shoot Fun Taiwan Challenge, a spin-off that brings an Amazing Race element to sight-seeing in Taiwan, which will air in September. Role-playing is given an interesting twist in Undercover Boss US (right: BBC Knowledge, Mondays at 10pm), in which the top dogs of big corporations don disguises and get their hands dirty in the lower echelons of their companies. Based on the popular British version, each episode of the reality show inserts a chief executive or director into the production line of their company. He or she shadows unsuspecting employees as they go about their daily duties, bonding over lunch and learning about their challenges and goals, as well as how they see the company overall. At the end of the episode, staff members are called in for the big revelation - and the boss generally promises to do the right thing. Cue awkward smiles. Though one can assume there is a fair amount of tactful editing to keep the light of respectability shining on the big corporations - such as DirecTV, Nascar, Chiquita Brands International, Mack Trucks and MGM Grand in this season - the process is surprisingly humorous, with the undercover head honchos often bungling the simplest of tasks and feeling humbled by the gruelling work and long hours. For those of us on the outside, the programme is an interesting peek into the workings of leading companies in industries from aviation and agribusiness to healthcare and education. Finally, Medical Anomalies (Discovery Channel, Wednesdays at 10pm) is not for the faint-hearted. Examining the most extreme cases of rare conditions medical experts have no name for, let alone a cure, the programme documents the struggles of human beings whose lives are severely affected by their unusual conditions. In a small village in India, Deepak was born with four limbs growing out of his chest. His partially formed twin continues to grow, parasitically feeding off Deepak's blood supply and threatening his survival. In Europe, Calvino has been regularly crying blood for the past two years and no one can explain why. In the US, five-year-old Payton has an extraordinarily rare condition where his skin falls off at the slightest touch. And on the mainland, 22-year-old Cheng has been dealing with a skin condition that causes fish-like scales to grow all over his body. While some of the diagnosis and surgery footage are best avoided by younger children, these stories not only shed light on the possibilities and limits of medical science but also the amazing strength of the human spirit.