Responding to increased traffic at its warehouses as people try to stock up on essentials during the COVID-19 coronavirus outbreak, Costco (NASDAQ:COST) introduced a major temporary change to its long-standing membership policies. The new rules are intended to reduce the number of shoppers physically inside a store at one time, helping to prevent exposure to the virus by improving social distancing.

The existing Costco membership policy allows a member to bring two guests into a store, along with the member's children. While only the member can actually buy items and children can't be left unsupervised, a single membership card ordinarily allows three adults and additional children into the store.

Shoppers in a warehouse store.

Image source: Getty Images.

However, starting on Friday, April 3, a Costco membership card only allows a total of two people to enter the store, according to today's update. The announcement only specifies "people," so it seems likely the rule allows a member to bring either one of their children, or one adult guest, into the warehouse.

Other coronavirus-related changes to store operations remain in place. The initial opening hour, from 8 a.m. to 9 a.m., from Tuesday through Thursday is reserved for members who are 60 years old or older and other people whose physical condition makes them more susceptible to coronavirus infection. Locations are also closing at 6:30 p.m. to allow additional time for a thorough cleaning.

The company's other coronavirus measures include per-member purchase limits on certain items, a temporary no-returns policy on toilet paper, hand sanitizer, rice, and several other items, and take-out only service at food courts.

Though traffic at Costco has begun to drop off, with the same happening at other big box retailers, the new restrictions on member guests to one person will remain temporarily in place until further notice.