While millions of Americans are at home, socially distancing to curb the spread of the coronavirus, fleets of men and women head out daily to make deliveries. Some drop off groceries and medicine, while others hand over marijuana strains of blue dream or sour diesel.

In over a dozen states, marijuana dispensaries and pot shops have been deemed essential services and remain open through lockdowns, and illegal deliveries are also on the rise. This worries medical experts, who say smoking and vaping damage the lungs, worsening symptoms and helping to spread the virus. The cannabis trade faces a new problem: keeping employees safe from the virus.

“Our business doubled: Every day is a Friday,” said the owner of Jack Flash, a cannabis delivery service in New York City, who spoke on the condition of anonymity because the sale of recreational marijuana is illegal in New York. “It’s just been really nonstop.”

Jack Flash employs a team of seven to deliver cannabis products to customers across all five boroughs of New York City from 10 a.m. to 11 p.m. daily. Customers find out how to place an order by word of mouth. There is only one rule: Buyers must retrieve their product and complete the transaction in the car, the owner said.