It is impossible to separate temperature from the idea of contrast in a dessert. The consumer perceives as contrasts even subtle shifts in temperature from one component of a dessert to the next, lending interest and excitement to the dessert.
Not every successful dessert features elements served at different temperatures. Sometimes a dessert composed of differently textured components is enough to engage the attention and please the palate of the person consuming it. But when appropriate, for example, serving a hot sauce with a cold mousse, or a pastry-based main element such as a tart or a warm soufflé with a cool, creamy drift of whipped cream, takes that dessert to a transcendent level where the whole is so much more than the sum of its parts. By itself, a warm soufflé is certainly texturally satisfying but becomes even more so when served with its whipped cream accompaniment. Adding one more texture by serving a crisp, thin cookie or a flaky puff pastry baton adds even more textural interest and gives the diner the opportunity to move from element to element, consuming bites of each in succession. With just a little thought and planning on the part of the dessert architect, the overall eating experience is thereby made more complex and more enjoyable.