As an experienced Model United Nations delegate, I can tell you those things go on forever and any human must use the restroom. So, it's customary to send a note to the chair of the committee to inform him/her of the situation and usually, once the speaker has finished, the chair will call a 5-10 minute un-moderated caucas. Also, in the United Nations, a representative must raise his/her hand to be acknowledged to speak.
