Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Heatmaps related to the interpersonal distance maintained between the subjects that simultaneously took part the test. The areas in which the distance between the subjects tended to 0 m are shown in red, while the areas in which the distance tended to the limit of 1.5 m suggested according to COVID-19 prevention measures are shown in blue. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
