Real-estate developers are building costly cold storage space before they even have tenants lined up. They're betting the risky move could be a winning investment as grocery deliveries surge.

· The country's once obscure cold-storage property sector is beginning to garner attention from investors who see big demand for temperature-controlled spaces. 
· The coronavirus pandemic prompted millions of Americans to shop for groceries online, creating demand for a new category of cold warehouses close to population...