MEMPHIS — It’s 11 a.m. and a bone-chilling 18 degrees as Joey Watts, wearing a picket sign that says “Locked Out,” trudges across an overpass overlooking the cereal factory, which has a big neon sign spelling out Kellogg’s in its red signature logo.

For more than three months, Kellogg has locked out Mr. Watts and 225 of his co-workers, barring them from returning to their jobs making Frosted Flakes and Froot Loops until their union agrees to a new contract. With the lockout lasting so long and the winter so brutal, emotions have been running high.

“It’s simple — Kellogg’s is a highly profitable company and just wants to pay people less,” said Mr. Watts, who has worked at the plant for 28 years. “It’s just plain greed.”

To the locked-out workers, Kellogg is yet another American company seeking to knock middle-class workers down a few pegs and chip away at their pay and benefits. But to Kellogg, the Memphis plant is a high-cost operation with above-market wages that badly need to be brought under control to make the plant competitive.