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).
Honour widows that are widows indeed. But if any widow have children or nephews, let them learn first to show PIETY at home, and to requite their parents: for that is good and acceptable before God. ( 1 Timothy 1:1 Psalm 5:3-4 ) Source: A King James Dictionary.