Concise Bible Dictionary:
The words in the originals imply “a burning heat,” so that there is no doubt that what is commonly known as “fever” is intended (Deut. 28:22; Matt. 8:14-15; Luke 4:38-39; John 4:52; Acts 28:8). The same Hebrew word is translated BURNING AGUE in Leviticus 26:16.
Strong’s Dictionary of Greek Words:
Meaning:
from 4445; inflamed, i.e. (by implication) feverish (as noun, fever)