Fever can support the immune system's attempt to gain advantage over infectious agents, such as viruses and bacteria, and it makes the body less favorable as a host for replicating viruses and bacteria, which are temperature sensitive. Infectious agents are not the only causes of fever, however.
Your sister's grandson is your great nephew. You are his great aunt (if you are a woman) or his great uncle (if you are a man).
The boy, 16, was killed by his sister, 15, on January 5 after she escaped the room her brother had locked her in and shot him in the neck. The older sister asked her younger sister to keep watch as she went outside and cut out the air conditioner of her parents' locked bedroom window to retrieve a pistol.