Doug Preszler wasn’t thinking about risk when he took a cashier job at a regional supermarket in eastern Iowa. But five months in, he has found himself at the forefront of a global crisis with little training or protection — save for the pocket-size bottle of hand sanitizer and Ziploc full of disposable gloves he brings from home each day.

The 51-year-old has told himself not to live in fear yet concedes he increasingly is. Even the most routine tasks are fraught: Accepting bills and giving change scare him the most, Preszler says. And he has run through so much hand sanitizer that his skin is cracking.

“I’ve been way more anxious this week,” he said. “They’ve started telling people, ‘Go to the grocery store as little as possible.’ And yet I’m going there every day.”

Next to health-care providers, no workforce has proved more essential during the novel coronavirus pandemic than the 3 million U.S. grocery store employees who restock shelves and freezers, fill online orders and keep checkout lines moving. Although the public health guidelines are clear — steer clear of others — these workers are putting in longer shifts and taking on bigger workloads. Many report being stressed and scared, especially as their colleagues fall ill to the highly contagious coronavirus that is responsible for more than 21,000 deaths in the United States alone.

Some liken their job to working in a war zone, knowing that the simple act of showing up to work could ultimately kill them. At least 41 grocery workers have died so far. They include a Trader Joe’s employee in New York, a Safeway worker in Seattle, a pair of Walmart associates near Chicago and four Kroger employees in Michigan, as well as employees at meatpacking plants and food processing facilities around the country. Thousands more have tested positive for the virus.