Two elderly women living near St. Louis and a man working in a Georgia tobacco field died yesterday in a heat wave that has grown increasingly dangerous, leading to the deaths of 35 people and causing more than 300 to become ill in the East and Midwest.

Temperatures soared from the 90s toward the 100s in much of the torrid zone, the worst hot spell since 300 people died in 1980. The dead in the current heat wave included 15 people in 100-degree Missouri and 10 in Georgia, including a man in his 30s who was jogging.

Relief came to the East Coast last night, but in the form of severe thunderstorms accompanied by high winds. Six people were injured when high winds overturned a camper trailer and uprooted tents in a camping area near Salisbury, Mass.

In St. Louis, authorities said that the prime victims of the heat were the elderly trapped in brick homes in neighborhoods where they feared to open the windows because of the city's high crime rate. A heat emergency was in force, and 50 civic cooling centers were open.

More than 300 cattle perished in South Dakota. Farmers in Monroe County, N.C., said they have lost 50 percent of their corn crop. State poultry farmers said mortality rates in broilers jumped from 1 to 5 percent in the last week.

Town after town across the heat belt warned residents that they had to cut down on lawn sprinkling or any other non-essential use of water.

On Wednesday night, 200 people watching or marching in a parade in Minneapolis were treated for heat exhaustion.