Multiple-Concept Example 8 reviews the approach that is used in problems such as this. A person eats a dessert that contains 160 Calories. (This "Calorie" unit, with a capital C, is the one used by nutritionists; 1 Calorie = 4186 J. See Section 12.7.) The skin temperature of the person is 35 .C and that of her environment is 23 C. The emissivity of her skin is 0.81 and its surface area is 1.3 m2. How many hours would it take her to emit a net radiant energy from her body that is equal to the energy contained in this dessert? Heat from environment Heat from To person Number i Units