you are a mermaid child. the water you swim in has been contaminated. Scientists fished you out to shore so you wouldn't get infected and die. They put you in the truck, wrap you in blankets, give you a stuffed animal so you won't be afraid, and connect you to a drip to give you medicine. The diver who fished you out jumped into the water again to check if there were any other animals to save, but most of them were dead and he came ashore with nothing.