Substituting for kicks

Just in time for April Fool's Day, the producers of "Undercover Boss" take a second crack at their knee-slapper concept with "The Substitute." This time around, they enlist the help of special effects artists, who help transform celebrities into regular-looking substitute teachers. The series kicks off with teen star Jace Norman (Nickelodeon's "Henry Danger") surprising a classroom of middle-schoolers.

6:30 p.m., Nickelodeon

Surviving the worst

Want to know how humans might survive the coming climate apocalypse? Meet your new role models: the plateau-jumping Gelada monkeys of Ethiopia's Simien Mountains, the ice-covered penguins of the High Arctic, the giant killer whales off the coast of Norway. British adventurer Bear Grylls leads a tour of the world's most extreme climates with "Hostile Planet," a six-part series exploring how wildlife adapts to the world's cruelest conditions.

8 p.m., National Geographic

Kimmel goes to Vegas

Jimmy Kimmel — aka the world's sweetest late-night host — heads to Las Vegas for five days of live shows from the Strip. The fun kicks off Monday with appearances by the Kardashian sisters (as in: Kim, Khloe and Kourtney) and dance-rock by the Killers. Rounding out the workweek are appearances by Vegas mainstays including James Taylor, Celine Dion and Mike Tyson. 10:35 p.m., Mon.-Fri., KSTP, Ch. 5