Fairly easy - only phone interviews. "First" round interview isn't an interview at all, it's just a phone call to schedule the next interview. They pick all interviews based on resume. Second round interview is over the phone (even if you're in the area), questions ranged from "How good are you with Excel?" to "Why Red Cross?" The Red Cross is all about their mission statement, so talk about that. Questions were not hard. Usually there is a third round interview, but it's the same as the second round interview only with a different team member.
Note: this format is the same for any ARC HQ Internship