By the end of the century, the Twin Cities area could see eight times as many deaths annually due to extreme heat as it does now, according to a study by the Natural Resources Defense Council (NRDC).

The projected increase -- from about 14 per year to 121 by century's end -- would be among the steepest experienced by 40 major metro areas. The authors said that is partly because extremely oppressive heat waves would be more of a shock to northern residents' systems.

But local officials said the area has already been preparing for extreme heat, developing a plan that involves cooling centers, monitoring of vulnerable residents and a restriction from shutting off electricity to people who haven't paid their bills. "Minneapolis has a very thorough and very robust plan," said Pam Blixt, preparedness director for the city health department.

"There's a lot we can do to prevent those sorts of numbers," said Kristin Raab, climate change project director for the Minnesota Department of Health. "We have been seeing trends of increased heat and increased humidity. Our role really is to help get the prevention message out."

Louisville and Detroit were projected by the study to face the greatest increases in heat-related deaths. A slight decline was seen for one city: Atlanta.

Nationally, the study projects a cumulative, 88-year total of 150,000 heat-related deaths above current averages, increasing over time but averaging about 1,700 additional deaths per year. The Centers for Disease Control and Prevention put the number of heat-related deaths annually in the United States from 1979-2004 at 334.

The study's authors were Larry Kalkstein, a professor of geography and regional studies at the University of Miami, and Daniel Lashof, director of the New York-based NRDC's climate and clean air program.

They urged aggressive action to curb greenhouse gas emissions, the primary cause of climate warming, as well as local programs to reduce the impact of intense heat on residents. The study, "Killer Summer Heat," is available at www.nrdc.org.

Bill McAuliffe • 612-673-7646