(Reuters) - Wal-Mart Stores Inc <WMT.N> said it was relaxing its dress code and raising the temperature at its stores as part of an effort to improve working conditions at its 4,555 U.S. locations.

Executives at the world's largest retailer made the announcement at a gathering of 3,000 workers brought to Arkansas this week before the company's annual shareholders' meeting due to be held on Friday.

The effort, which includes a new training program and upgraded handheld terminals for department managers, is being billed as a sign that management was listening to some one million hourly workers it employs in the United States.

Wal-Mart has long faced criticism over pay and hours for many of its employees.

"My job is to make your life easier," Greg Foran, head of the retailer's U.S. operations, told the workers at the Bud Walton Arena in Fayetville, Arkansas.

Under a new dress code due in July, store workers will be allowed to wear black and khaki denim pants in addition to khaki trousers permitted by the existing code. Workers with physically demanding jobs will be allowed to wear blue denim and T-shirts.

Wal-Mart said it would raise the temperature in its stores to address worker complaints that they are too cold. The retailer controls temperatures centrally at its headquarters in Bentonville, Arkansas.

Foran presented examples of store workers taking initiative to find and promote hit products as behavior to be rewarded. The company wants to rev up U.S. sales, which were below market expectations in the latest quarter.

He encouraged employees to greet and help shoppers find what they need, and vowed that U.S. stores would be "clean, fast, friendly and in stock" by the crucial year-end holiday shopping season.





(Reporting by Nathan Layne in Faytetteville, Arkansas)