In three months, Sheri Clemmer, associate meeting planner for the Seventh-day Adventist world church, will be working up to 19 hours straight, answering calls on two cell phones and a radio and potentially walking several miles worth of convention center floor a day.

Clemmer says adrenaline and lots of prayer keep her going during the 11 days of General Conference Session, the business meeting of the Adventist world church. Held every five years, the meeting is a massive undertaking, with over 70,000 people attending on some weekends.

The 2010 Session, scheduled for June 23 to July 3 in Atlanta, Georgia, will be Clemmer's second meeting as associate planner. Her interest in the event began 10 years earlier, when she attended for the first time as an exhibitor at the Toronto meetings.

"One night I walked out of the building and I was just surrounded by the crowd," Clemmer says. "I couldn't see anything but people. Some people become claustrophobic in those situations, but to me it was just awesome. All those people were my brothers and sisters."

When Clemmer was offered the associate meeting planner job in 2003, she enthusiastically accepted.

"I thought, 'That would be awesome, then I would really be able to go all the time!'"

Clemmer's excitement about her task is visible, despite the enormity of the undertaking. The Session planning committee has 23 subcommittees, many with their own sub-sub committees. It also takes more than 300 technical staff to perform Session tasks like news reporting, taking minutes at meetings and staffing the exhibit hall, Clemmer says.

The event itself costs $6 million, but world church Treasurer Bob Lemon estimates the total cost is double that once travel, hotel and delegate expenses are factored in. More than 2,000 delegates from the church's 13 world regions are chosen to vote on policy items addressed at a Session, all of whom must be housed and fed for nearly two weeks.

Finding a suitable location is the first big challenge, Clemmer says. A city must have a covered stadium with an adjacent or nearby convention center, plus hotels with 6,000 rooms within walking distance.

Should a city meet those requirements, the sports teams themselves can prove an obstacle. If the dome is a baseball field, teams often say they can't have away games for 19 nights straight, Clemmer says. In addition to the 11 days of meetings, eight days are scheduled for setup and teardown.

"We're almost restricted to football stadiums now," she says.

Once cities are narrowed down, the Session planner sends out a 'request for proposal form' to potential locations. Clemmer says the goal is to have three cities bid, but that doesn't always happen - only two cities bid for the 2015 Session.

Each city offers concessions to attract the business of the Adventist Church. In San Antonio, the location of the 2015 Session, the dome and convention center are an eight-minute walk apart. Clemmer says she requested that an awning cover the sidewalk running between the two locations, with water stations at several points between the buildings. The city complied.

After the location is chosen at one of the church's two yearly business meetings, the Session planner begins signing contracts with the venues and nearby hotels. Once the paperwork is done, the planner hires a decorator, arranges for shipping to the venue and assigns conference and office rooms and exhibitor space.

"What you do is get the floor plans of the building and you have to start plugging in who goes where," Clemmer says. "That takes a long time -- it's a giant puzzle you put together. You have to make sure ... people that need to be near each are near each other, and you have to do it in the confines of the building."

In the end, all the pieces come into place -- just in time to start the process over again. Clemmer says Session planners like to present a site for vote nine years in advance.

"That means I actually start working on locating options for consideration ten years in advance," Clemmer says. "The last two quarters of this year I will be focusing on options for 2020."

Clemmer puts the endless cycle of preparation in perspective by saying GC Session is much bigger than any individual or committee.

"This is God's meeting," she says.