Armed with hand sanitizer and disinfectant wipes, Christina Rice is among the hundreds of thousands of gig workers who deliver food and other household staples and who have suddenly found themselves in higher demand at the front lines of the coronavirus pandemic.

As the spread of COVID-19 accelerates, more people are staying at home and grocery-delivery service demand has boomed — and in an economy where many workers have at least temporarily lost their retail jobs overnight, the delivery services are hiring.

The delivery workers have become a vital resource not only for people in at-risk groups for the disease but also for parents who are doing double or triple duty as their children's schools closed, online learning is ramping up and their own jobs have shifted to telecommuting.

Delivery services such as Shipt, Instacart and Amazon Prime Now have been so overwhelmed by a surge in demand that it has become challenging to snag a delivery window. Some deliveries are being scheduled several days out, if at all, instead of a couple hours.

The services and delivery workers also have changed how they work to protect both the workers and the people receiving the food, for example moving to contactless delivery.

Rice, a single mother of two in Minneapolis, started working for Target's same-day delivery service Shipt last year after losing her job as a paralegal. She is taking extra precautions these days such as no longer directly handing bags of groceries to customers.

"Before, I would actually meet them at the door and give them everything," Rice said as she filled a shopping cart at a local Target with paper towels, ginger ale and Kool-Aid Jammers for her next delivery. "But almost everything I've done today has been porch drops. I let them know I just dropped it off and I'm walking away and then they grab it."

A Cub spokesman said online ordering for delivery and curbside pickup was up more than 175% last week. Instacart — which provides delivery from Cub, Aldi, Costco, Lunds & Byerlys and Jerry's Foods — said it saw the highest customer demand in its history over last weekend.

"Much as with our in-store experience, Instacart is experiencing unprecedented demand in this area and asks for your patience with the shoppers and delivery personnel from Instacart," Gerald Melville, president of Fresh Thyme Farmers Market, wrote in an e-mail to customers last week.

As the services try to keep up, Shipt is looking to hire an additional 2,000 shoppers in the Twin Cities. Amazon and Walmart each want to recruit an additional 100,000-plus workers across the country to do a number of jobs, including handling online orders. And Lunds & Byerlys, which has seen online shopping nearly double, also is staffing up in this area, as are other grocery stores.

As more people try out grocery-delivery services for the first time or use them more often in the coming weeks, retail experts said this could be a tipping point for online groceries.

"It's going to be habit-forming in a way that will have lasting effects," said Andrew Lipsman, an analyst with eMarketer.

Groceries had been one of the last major categories to catch on online as many consumers still prefer to go to the store and pick out their own produce. According to Nielsen, only about 4% of grocery sales last year in the U.S. were done online, though it's rapidly growing.

While many consumers may get frustrated by not being able to easily get a delivery window, Lipsman said most will be more forgiving given the circumstances.

"They know these are no ordinary conditions," he said.

In the meantime, some workers are anxious because delivery jobs these days come with higher risks because of their exposure to the public.

Not everyone is eager for this kind of work right now.

One Twin Cities Shipt shopper, who asked not to be named, has temporarily stopped her side job because she is a nurse and wants to make sure she stays healthy for her patients. She said she knows some other Shipt shoppers who also have stopped their delivery gigs because they have underlying health conditions or have older relatives living with them.

Magan Shire of Minneapolis has been making deliveries for Amazon Prime Now for about two years. He admits he's a little more nervous about his job these days. He wears gloves to make deliveries and uses lots of hand sanitizer.

"I try not to touch my face, my nose or eyes," he said.

For the most part, he doesn't have any face-to-face contact with customers, leaving packages on doorsteps. But with alcohol delivery, he is required to check customers' driver's licenses. In one recent such delivery, a customer warned him that she was under quarantine.

"I told her to put her license on the floor," he said. "I just scanned it from there and left the stuff there so she could pick it up."

Other Prime Now delivery workers said the most unsettling part of their jobs these days is going into apartment buildings where they have to touch door handles and elevator buttons.

There are other added challenges, such as more items being out of stock.

Rice, the Shipt shopper, said it takes her twice as long now to fill an order because there's more back-and-forth communication about substitutions.

Since she is paid a percentage of the order's value, she doesn't get paid more for the extra time.

"But people have been pretty good with tipping," she said. "It's about double what I would normally get in tips, so it's kind of making up for it."

Staff writer John Ewoldt contributed to this report.