About two dozen people have been treated for illness during a rally featuring President Obama at Bowie State University.*
Prince George's County Fire and EMS spokesman Mark Brady tells WTOP numerous ambulances have been sent to the rally after people started fainting and became dizzy.
The problems could be related to warmer temperatures today. Brady says crowds at the rally were outside and packed shoulder to shoulder.
Two people have been taken to the hospital so far, Brady says. The rest have been treated at the scene.
The president still gave a stump speech at the event despite the audience's sicknesses. House Majority Leader Steny Hoyer and Sen. Benjamin Cardin also spoke at the event.
(Editor's note: This is a breaking update. This story may change as more information becomes available.)
*The number was updated from 15 to about two dozen.
And here's a flashback compilation clip of the many fainting incident during Obama's campaign for president: