[Wendigo]

It's very unlikely for a mage to get up to 190 fatigue on his/her own, because as soon as the mage goes over 100 fatigue he goes unconscious, stops casting & starts recovering 5 fatigue/round.

Thus, unless your mage used powerful magics requiring gems or was a comunion slave such high fatigue level must most probably be due to an outside source. If the mage was a heat resistant Demonbred I would bet on a 'fatigue due to cold' source: either a nearby critter with a cold aura (Ice Devil...), or a Water mage casting Grip of Winter.