Almost every person suffers a headache or fever occasionally in his/her life.
Whilst this may seem to be a condition of discomfort,
it is a blessing in disguise.
Rasulullah (Sallallahu Alaihi Wasallam) has said: “As a person suffers a headache or fever,
his/her sins are erased to such an extent that even if his/her sins were equal to the mount of Uhud,
they will be reduced to the amount of a mustard seed