First and foremost, the health and safety of the employee must take precedence. Should 911 be called? Is there a contact number for someone to call? Is the employee working a physical job that could further endanger him and/or other employees? These are questions to ask and ascertain, and these are the immediate obligations.
Many health issues are not readily apparent, and any resulting impact on work performance should be addressed strictly as performance issues. It is not the employer’s obligation to pry into employees’ health issues.
If the employee discloses a health issue, however, that opens the door to possible accommodation. In this situation, the health condition also is opened up to the employer due to the employee’s seizures in the workplace. The employer is now obligated to engage in the interactive process with the employee to determine effective reasonable accommodations.
You can find more information on Reasonable Accommodation of Disabilities in the HR Library.