Teresa Heinz Kerry (search) was back on the campaign trail at Labor Day parades in Pittsburgh and Philadelphia after a brief hospitalization over the weekend in Iowa because of an upset stomach.

Heinz Kerry, the wife of Democratic presidential candidate John Kerry (search), told union laborers during a Labor Day rally that the country's leaders need to fight as hard to protect workers as they do to ensure homeland security.

"There is no war worth fighting if the people in our country are not defended and not protected in their jobs, in their life, in their schools and in their health care," Heinz Kerry told a crowd of several hundred supporters during an AFL-CIO (search) rally in Philadelphia. "Security is that which is in your home."

She said that if John Kerry is elected, he would offer tax breaks to companies that keep jobs in the United States, work to cut health care costs and make sure that America doesn't go it alone when fighting battles overseas.

"It is wrong trying to go it alone in a war that we didn't need to get into and giving the American people the bill," she said.

The afternoon rally, which ended Philadelphia's Labor Day parade, was Heinz Kerry's second campaign stop Monday. Earlier in Pittsburgh, Heinz Kerry marched with several groups, including a local of the Service Employees International Union.

Heinz Kerry, who had been taken to a hospital briefly Saturday in Iowa with stomach pains, didn't address paraders in Pittsburgh, but watched unions march past the Steelworkers' union building.

She stood with state and local Democratic politicians, including Gov. Ed Rendell, state Treasurer Barbara Hafer and Allegheny County Executive Dan Onorato. She also posed for pictures and shook hands with paraders.

Heinz Kerry had also planned a stop in the Lehigh Valley, but canceled it to rest following her brief hospitalization. She was treated and released at a hospital in Mason City, Iowa, on Saturday after complaining of an upset stomach; she had just finished a private meeting with a group of local Democrats to talk about health care.