Workers assemble a temporary field hospital at the Pacaembu Stadium during the outbreak of coronavirus disease (COVID-19) in Sao Paulo, Brazil, March 23, 2020. In Sao Paulo, the Pacaembu stadium is being transformed to become a field hospital to treat coronavirus cases. REUTERS/Amanda Perobelli

Workers assemble a temporary field hospital at the Pacaembu Stadium during the outbreak of coronavirus disease (COVID-19) in Sao Paulo, Brazil, March 23, 2020. Sao Paulo, the country's biggest city, is slated to begin a lockdown on Tuesday (March 24). REUTERS/Amanda Perobelli

The shadows of workers are seen as a worker assembles a temporary field hospital at the Pacaembu Stadium during the outbreak of coronavirus disease (COVID-19) in Sao Paulo, Brazil, March 23, 2020. Several Brazilian states have begun closing shopping malls and schools, and banning public meetings, soccer matches and religious assemblies. REUTERS/Amanda Perobelli

Workers assemble a temporary field hospital at the Pacaembu Stadium during the outbreak of coronavirus disease (COVID-19) in Sao Paulo, Brazil, March 23, 2020. REUTERS/Amanda Perobelli

Workers assemble a temporary field hospital at the Pacaembu Stadium during the outbreak of coronavirus disease (COVID-19) in Sao Paulo, Brazil, March 23, 2020. REUTERS/Amanda Perobelli