Institutio Oratoria

Otherwise your delicate, over trained voice will succumb before any unusual exertion, like bodies accustomed to the oil of the training school, which for all the imposing robustness which they display in their own contests, yet, if ordered to make a day's march with the troops, to carry burdens and mount guard at night, would faint beneath the task and long for their trainers to rub them down with oil and for the free perspiration of the naked limbs.

Who would tolerate me if in a work such as this I were to prescribe avoidance of exposure to sun, wind, rain or parching heat? If we are called upon to speak in the sun or on a windy, wet or warm day, is that a reason for deserting the client whom we have undertaken to defend? While as for the warning given by some that the orator should not speak when dyspeptic, replete or drunk, or immediately after vomiting, I think that no sane person would dream of declaiming under such circumstances.