The renowned plant Echinacea is thought of, homeopathically, as a ‘blood cleaner’. It is useful for all conditions tending towards septic states.
Therefore it finds good use for boils and abscesses "When boils progress to the stage where they appear about to 'point' then stop and do not suppurate, Echinacea is the remedy." [Anshutz]
It is also appropriate to consider for those people who work hard and are run down by too much work or study. Often as soon as they take a vacation they become ill, maybe with a cold or the flu or a sore-throat.
Chilly people in general
Better from rest
Worse from physical or mental work
Desire cold drinks
Boils and abscesses
Burns
Colds and Flu
Sore throat
Sunburn