. >> ninan: dr. jon lapook is our chief medical correspondent. dr. lapook, what do you see in sh video. >> reporter: first it's important to point out i'm not mrs. clinton's physician and i'm trying to put things in perspective based on limited information. but what i see in this video is someone unstedy and wobbly but conscience on a hot and humid day in new york city like today, a likely possibility is something relatively innocent called a vasovagal reflex when a person's blood pressure or pulse drop causing diziness or fainting. today she was apparently standing for more than an hour in hot humid weather it was 80 degrees with over 50% humidity wearing pants and long sleeves. a total setup for a vasovagal. the normal immediate treatment is for a person to lie flat. that way it's easier for blood to get from the heart to the head. one very good sign is that mrs. clinton went to her daughter's apartment rather than to a medical center and that she soon emerged apparently looking and sounding fine. >> ninan: we know mrs. clinton has had health probl