It might mean a temporary breakdown from overfatigue or a sickening for deadly illness.
Phillis, you are just feverish from overfatigue and sitting so long in one place, for you are used to running about.
They suggest improvements in conditions and are awake to signs of illness or overfatigue.
It's the result of accumulated poisons of overfatigue, long hours, overwrought nerves, "the military discipline of the mills."
overfatigue and exhausting physical exertion should be avoided.
This depends in large degree on general health62 and nutrition, with freedom from overfatigue.