The Supreme Court on Thursday affirmed a sex discrimination jury award for a female forklift operator who was transferred to a more physical job after she filed a lawsuit accusing her employer of sexual harassment.

By a 9-0 vote, justices said that Sheila White was improperly punished with a suspension for 37 days over a Christmas holiday and a transfer from operating the forklift to doing more physical work as a yard worker.

Justice Stephen Breyer wrote that White did receive back pay. But he said she and her family had to live 37 days without any income.

Click here to read the ruling.

"Many reasonable employees would find a month without a paycheck to be a serious hardship," Breyer wrote, adding that "an indefinite suspension without pay could well act as a deterrent, even if the suspended employee eventually received back pay."

The high court's ruling tilts the balance of power in employment settings toward employees by establishing a broader legal standard for retaliation claims, an area of litigation that has exploded in recent years.

Under the high court's standard, employers are liable for unlawful retaliation if their actions "interfere with an employee's efforts" to ensure that he or she is not discriminated against in the workplace, Breyer wrote.

The anti-retaliation provision of the 1964 Civil Rights Act "seeks to prevent harm to individuals based on what they do, i.e., their conduct," such as filing a discrimination complaint, Breyer said.

Breyer said employees who complain of discrimination are not immune from "those petty slights or minor annoyances that often take place at work and that all employees experience."

He said trial courts must determine on a case-by-case basis whether "reasonable" employees would be intimidated by actions taken by employers against them.

"Context matters," Breyer wrote.

A schedule change may not bother many workers, he said, but it may matter greatly to a young mother with small children. Or, Breyer said, a supervisor's failure to invite a worker to lunch would seem trivial unless the luncheon was a weekly training session crucial to the employee's advancement.

Retaliation claims by workers have more than doubled over the past decade, comprising more than 30 percent of the Equal Employment Opportunity Commission's caseload and costing more than $130,000 each to resolve, according to Burlington's court filings.

White was the only woman working in the rail yard for the Burlington Northern Santa Fe Railway in Memphis, Tenn.

After she accused her supervisor of sexually harassing her, a company investigation led to the foreman's suspension and enrollment in sensitivity classes. But White also was transferred to work as a regular track worker, a more physically demanding job than operating a forklift.

The railroad eventually rescinded its decision to suspend White — clearing her of insubordination charges — and compensated her for back pay.

A jury rejected her sex discrimination charge but found in her favor on the retaliation claim, awarding her $43,000.

The case is Burlington Northern Santa Fe Railway v. White, 05-259.