Wearable-based certification of a premises as contagion-safe

A system configured to certify a premises as contagion-safe, comprising:

• wearable devices configured to take measurements of users comprising photoplethysmogram. signals of the users and temperature signals of the users;
• and
• a computer configured to:
• calculate health scores of the users based on measurements of the users taken while the users were not on the premises;
• identify which of the users are non-symptomatic users based on their health scores reaching a threshold;
• authenticate identities of the non-symptomatic users based on at least some of their measured physiological signals;
• and
• certify the premises as contagion-safe responsive to determining that the non-symptomatic users whose authentication was successful comprise at least a certain predetermined proportion of all of the users who visited the premises.

A method for certifying a premises as contagion-safe, comprising:

• receiving measurements of users measured with wearable devices while the users were not on the premises, wherein the measurements comprise photoplethysmogram signals of users and temperature signals of the users;
• calculating health scores of the users based on the measurements;
• identifying which of the users are non-symptomatic users based on their health scores reaching a threshold;
• authenticating identities of the non-symptomatic users based on at least some of their measurements;
• and
• certifying the premises as contagion-safe responsive to determining that, from among the users, only non-symptomatic users, whose authentication was successful, entered the premises during a predetermined period.