For the duration of the pandemic, have the self booking clients prompted to confirm that they are not exhibiting a fever...
...not sick currently, not in contact with a COVID case, and willing to observe the salon and local health department's policies for the planned appointment. (if the salon and/or business partner enables this setting).
Depending on state, city, and salon; there are many concerns regarding making sure that salons are best equipped to continue on during this crisis. Having this prompt that the clients would have to check off or affirm will provide Boulevard salons one further thing to share with their staff and clients that the salon (and software suite) are doing in the name of better public health compliance.
Further guidance for each location to do this as part of phone call bookings is of course advised. Some salons may even prefer the confirmation emails and texts to have similar verbiage in the meantime.