SYDNEY, Australia (AP) _ Brigitte Muir is cooling off to warm up for a planned assault on Antartica's tallest mountain.

Mrs. Muir, 32, who hopes to become the first woman to climb the highest peaks on each of the world's seven continents, plans to spend 40 hours with her four-man support crew plan at 22 below zero temperatures in a fish market freezer starting Saturday afternoon.

''The freezer will simulate Antarctic conditions for my support team as we prepare to climb Mount Vinson, which at 5,140 meters (16,863 feet) is Antarctica's highest mountain,'' she said Wednesday.

Since reaching the summit of Mt. McKinley, North America's tallest mountain, in 1988, Mrs. Muir has conquered Mt. Kilimanjaro (Africa), Mt. Aconcagua (South America), Mt. Kosciusko (Australia) and Mt. Elbrus (Europe).

''After climbing Mount Vinson, I will then tackle the big one - Mt. Everest,'' she said. ''An American woman has already climbed all but Mt. Everest, so I've got to do Mt. Vinson this year and Mt. Everest early next year, so I can take the record before her.''

Joining her in the freezer will be her husband, cameraman John Muir; freelance photographer and writer Jonathan Chester, cameraman Glenn Singleman and sound recorder Michael Gatehouse.