Definition and Context:
In biblical times, fever was understood as a significant ailment, often seen as a manifestation of divine displeasure or a test of faith. It is mentioned in both the Old and New Testaments, reflecting its prevalence and the concern it elicited among ancient peoples. Fever, as a symptom, was not ascribed to specific diseases as in modern medical understanding but was recognized as a serious condition requiring divine intervention or healing.

Old Testament References:
In the Old Testament, fever is often associated with divine judgment or punishment. For instance, in Leviticus 26:16, God warns the Israelites of the consequences of disobedience: "then I will do this to you: I will bring upon you sudden terror, wasting disease, and fever, which will destroy your sight and drain your life." Here, fever is part of a series of afflictions meant to turn the people back to God.

Deuteronomy 28:22 also lists fever among the curses for disobedience: "The LORD will strike you with wasting disease, with fever and inflammation, with scorching heat and drought, with blight and mildew, which will plague you until you perish." These passages reflect the belief that physical ailments, including fever, were directly linked to spiritual and moral conduct.

New Testament References:
In the New Testament, fever is depicted in the context of Jesus' healing ministry, demonstrating His authority over sickness and His compassion for the afflicted. One notable instance is the healing of Peter's mother-in-law, as recorded in Matthew 8:14-15: "When Jesus arrived at Peter’s house, He saw Peter’s mother-in-law sick in bed with a fever. So He touched her hand, and the fever left her, and she got up and began to serve them."

Similarly, in Mark 1:30-31, the account is given: "Simon’s mother-in-law was sick in bed with a fever, and they promptly told Jesus about her. So He went to her, took her by the hand, and helped her up. The fever left her, and she began to serve them." These passages highlight Jesus' power to heal and His willingness to restore individuals to health and service.

Theological Implications:
From a theological perspective, fever in the Bible serves as a reminder of human frailty and the need for divine intervention. It underscores the belief in God's sovereignty over all aspects of life, including health and sickness. The healing of fever by Jesus is seen as a testament to His divine nature and His role as the Great Physician, who not only heals physical ailments but also addresses spiritual needs.

Practical Applications:
For believers, the biblical accounts of fever and its healing offer encouragement to seek God's help in times of illness. They are reminded of the importance of faith and prayer in the face of physical challenges. The accounts of healing also inspire Christians to serve others, as exemplified by Peter's mother-in-law, who, upon being healed, immediately began to serve Jesus and His disciples.

In summary, fever in the Bible is more than a mere physical condition; it is a symbol of the broader human experience of suffering and the hope of restoration through divine grace.