1. Animal Planet’s series “Monsters Inside Me” returns on Oct. 2 with more harrowing stories about viruses, parasites and foreign objects that find their way into the human body. Scary stuff.
2. Wildlife filmmaker Kim Wolhuter gets extremely up close and personal with a family of cheetahs in the Discovery special “Man, Cheetah, Wild,” premiering on Oct. 3.
3. On Oct. 6, Nat Geo Wild presents three episodes of “Animal Fight Night,” featuring epic battles between creatures for dominance. “Savannah Smackdown” includes lions, hippos and giraffes; “Rumble in the USA” includes bison, wolves and prairie dogs; and “Beach Brawl” focuses on coastal creatures such as polar bears, Tasmanian devils and sharks.
4. Discovery Fit & Health’s “Untold Stories of the ER” returns for its eighth season on Oct. 6, taking viewers inside the hospital to tell dramatic, unusual, and sometimes humorous real-life stories that unfold in the emergency room.
5. Sundance Channel’s six-part unscripted series “Dream School” gives troubled high school dropouts a chance to start over by teaming them up with a faculty like no other. Filmmaker Oliver Stone, civil rights activist Jesse Jackson, and finance guru Suze Orman will teach classes, as will wildlife expert Jeff Corwin, who will teach biology and ecology, Fabien Cousteau (physics) and environmental activist Chris Jordan (photography). Class begins Oct. 7.
6. A year after Superstorm Sandy devastated the East Coast and the Caribbean, PBS’ “Nova” presents “Megastorm Aftermath,” a sequel to its “Inside the Megastorm” that examines the storm’s cause and what we can do to prepare ourselves the next one. It premieres on Oct. 9.
7. On a special edition of Animal Planet’s “Too Cute,” favorite felines are revisited while “Growing Up.” It premieres Oct. 12.
8. PBS “Nature” marks its season premiere on Oct. 16 with “Saving Otter 501,” a documentary about the Monterey Bay Aquarium’s attempt to save a stranded orphan otter, nurse it back to health, and teach it to fend for itself in the wild.
9. PBS “Nova” launches a second season of the cutting-edge technology series “Making Stuff" on Oct. 16 with “Making Stuff Faster.” Subsequent episodes in the four-part series, hosted by David Pogue, include “Making Stuff Wilder,” "Making Stuff Colder” and "Making Stuff Safer.”
10. Premiering Oct. 21, the HBO documentary “Life According to Sam” follows the Berns family, parents who are doctors who’ve spent more than a decade trying to save their son from the rare and fatal premature aging disease called progeria.
11. The acclaimed documentary film “Blackfish,” about what happens to killer whales in captivity, focuses on Tilikum, the Sea World orca that killed his trainer in 2010. It will premiere on CNN on Oct. 24.
12. “A Shot to Save the World,” a documentary about the fight to eradicate polio, premieres Oct. 24 on Smithsonian Channel.
13. Nat Geo Wild celebrates Halloween with a three-part special on Oct. 26 called “The Monster Project.” Comedian Judah Friedlander (“30 Rock”) hosts this fun foray into cryptozoology — mythical creatures that may or may not exist — going in search of such fabled icons as the chupacabra, the Jersey Devil, Lake Champlain, Vermont’s Champ (the American answer to Scotland’s Loch Ness Monster), and a monster mash-up of a man, goat, bat and horse.
14. The new Animal Planet “Alaska Gold Diggers” follows a California mom and her four daughters to Alaska to reopen their late grandfather’s gold mines. It premieres Oct. 10.
15. The people who shoot images of the most breathtaking landscapes and iconic creatures in the world are celebrated in “National Geographic Photographers: The Best Job in the World,” which will be simulcast on National Geographic and Nat Geo Wild on Oct. 11. In field footage and interviews, lens masters reveal how they captured their most magical images.
16. “Access Hollywood’s” Billy Bush travels a long way from Tinseltown to Nepal to join in the fight to save endangered rhinoceros from poachers and spread awareness of their plight in “Chasing Rhinos,” a special airing on Nat Geo Wild on Oct. 13.
17. The new Nat Geo series “Big Bad Wood” follows four Boston-area tree-trimming crews as they work in challenging, dangerous environments. It premieres Oct. 17.
18. Premiering Oct. 17, Weather Channel’s new series “The Tipping Points: 7 Places on Earth Where Climates Changed” visits the Amazon rain forest, Greenland ice sheet, Himalayan glaciers and other locales where global warming’s effects are a cause for concern because they have already had a dangerous impact on global ecosystems.
19. “Don’t Try This at Home” — that’s the message and the title of the Nat Geo special (and pilot) that examines the science behind the Web’s most viral fails and why they went so wrong. It airs Oct. 18.
20. Smithsonian Channel’s series “Terror in the Skies,” which examines airline flight near-disasters, will air an episode called “Nature Strikes Back” on Oct. 20, including a Turkish Airlines plane struck by lightning, a China Airlines flight hit by runaway winds, and the bird strike that caused the “Miracle on the Hudson” water landing in 2009.