BOSTON (AP) — Get out your favorite Sailor Moon costume and grab a bottle of water. The Boston Comic Con is this weekend, and it's forecast to be a hot one. From Friday through Sunday, comic and costume fans will gather at the Seaport World Trade Center for a line-up of contests, panels and celebrity appearances.

Here are some things to know about the Boston Comic Con:

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CELEBRITIES

People-watching won't be limited to the costume-clad fans; several celebrities are being featured at the convention, too. The marquee name is Marvel Comics' Stan Lee, creator or co-creator of such characters as Spider-Man, the Hulk, X-Men and many more. Other celebs who will sign autographs include Billie Piper, made famous in the "Doctor Who" sci-fi show; Judah Friedlander, a comedian who made it big on "30 Rock;" and Hayley Atwell, the actress who plays Agent Peggy Carter in Marvel movies and on TV.

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EVENTS

Everything leads up to Sunday, when the annual costume contest is held that carries a $1,000 grand prize and countless questions from future employers. It runs from 2 p.m. to 5 p.m. Other events dripping in geeky greatness include a Friday panel of comic editors giving tips to aspiring artists and a Saturday auction of valuable comic art.

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SIDESHOWS

Between panels and people-watching, the convention will show movies throughout the weekend, ranging from classics like "Attack of the 50 Foot Woman" to a documentary on costume play. Gamers will also have their pick of several tournaments hosted by Cambridge's Pandemonium Books & Games.

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WEATHER

It won't be ideal weather for a full-body Chewbacca costume, but for those who are compelled to swath themselves in fur, fabric or foam, bring water. The National Weather Service is forecasting three steamy days on Friday through Sunday, with each one approaching 90 degrees. Boston's mayor urged people this week to stay hydrated and rest often in the shade if they'll be outside.

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SURPRISES

Comic conventions around the U.S. have had their share of memorable surprises. "Star Wars" star Harrison Ford made a surprise appearance at the flagship San Diego convention this year. Last year, George Clooney made an unexpected appearance in New York. No word yet who might show up in Boston.