Answer
$0.316L$
Work Step by Step
The additional heat from the person causes the water to evaporate. the water is at approximately room temperature, so use the heat of vaporization at room temperature as discussed on page 399.
$$Q=mL_v$$
$$m=\frac{Q}{L_v}=\frac{185kcal}{585kcal/kg}=0.316kg=0.316L$$