Romeo & Juliet

It's not improbable that William Shakespeare had someone who looked a lot like Leonardo DiCaprio in mind when he created Romeo, a youthful hero at once innocent and reckless. It is, however, unlikely that he imagined Romeo suffering from Montezuma's revenge, which has, on this January day, already taken its toll on DiCaprio in a hotel bathroom in Mexico City. His lovely Juliet, played by Claire Danes, is over a bout with the flu that caused production to close for a few days, but her mother, who came down to Mexico to be with her, is just getting out of the hospital with pneumonia. The director, 33-year-old Baz Luhrmann, whose novel idea it was to do Shakespeare in sharkskin, set amid the baroque grime of Mexico City, is sitting in Chapultepec Park, a tissue in one hand and a bottle of vitamin C in the other. The man next to him, doubled over, looking miserable, fighting dizziness by bowing his head to his lap? That's the cinematographer.

As German shepherds and armed guards patrol the Renaissance-style grounds of Chapultepec Castle, a history museum that serves as the exterior of the Capulets' home, the omnipresent smog settles over the city below. Crew members paraphrase the local newspaper's version of a weather forecast: ''The carbon monoxide level will be dangerous, but the dioxide won't be so bad.''

The challenges of Luhrmann's Romeo and Juliet, which attempts to combine old language, modern attitudes and settings, South Beach style and Latin exotica, all while shooting on a location chosen for its no-frills dirt cheapness, are considerable to begin with. With today's coughing and sneezing, they become impossible. Word is passed via walkie-talkies: The set is closing for the day. While the film's $14.5 million budget leaves little room for running over schedule, the editors aren't panicked at the prospect of no dailies to screen; they're all sick as well. ''What can you do?'' asks the on-set Mexican doctor. If it's not the water, it's ''the pollution, the exhaustion,'' the altitude headaches, the nosebleeds, and the stomach ailments. Halfway through the 72-day shoot, the combination of all of the above will knock the crew out of commission for four days.

Sure, the course of true love never did run smooth, but this is ridiculous.

With American accents, sharp camera angles, and a soundtrack that MTV audiences can relate to (the music producer, Nellee Hooper, has worked with Madonna and U2), R&J, which opens in October, is hardly the project Twentieth Century Fox had in mind when it contacted Luhrmann two years ago, after the release of his critically acclaimed Australian comedy Strictly Ballroom, and told him to write his own ticket. ''They got very nervous,'' admits Luhrmann, whose first step was to lure DiCaprio to Australia for a run-through of an early script soon after the actor's Oscar nomination for 1993's What's Eating Gilbert Grape.

The director, a former dancer who glides across sets, dresses for work in immaculate linen suits, and is given to such pronouncements as ''It will be abstractly clear,'' wasn't an instant hit with DiCaprio, and it wasn't simply because he could offer only scale wages. ''Most of the movies I do, I don't get paid a lot of money,'' DiCaprio says. (''Maybe I shouldn't say that,'' he adds quickly. ''People will get used to not paying me a lot of money.'')