The story is supposed to begin at morning time but the sun is located over the ocean, indicating that it's really sometime in the late afternoon.
Amanda and Steve wear their HazMat gear into both Mark's house, the house of the guy who died on the beach and another dead person. At no time is there any indication that they decontaminate the suits before taking them off.
While talking Charlie and Dr. Sloan say they each have type O blood. However, they don't say anything about the Rh factor (positive or negative), a potentially fatal issue that doctors wouldn't ignore.