I should start by saying that a room temperature biga is not bizarre sex act that only frat boys are capable of defining. It is an Italian pre-fermented dough. Bigas, like poolishes and pate fermentes, are flour/water/yeast mixtures which ferment overnight (or longer) to extract flavor from a portion of a bread's final dough. I typically follow Reinhart's pre-ferment recipes, which call for the pre-ferment to be refrigerated after an initial 3-4 hour rise, but I decided to veer away and try something different. Reinhart calls for the refrigeration of the pre-ferment to slow the yeast's reproduction and feeding. The longer the yeast feast (assuming ample food for the yeast supply), the more flavorful the bread will be. At some point, the yeast will eat all of the simple sugars in the flour, break down all the starches, and leave you with a puddle of very sour, wet dough. Also, without any food, the yeast will go dormant, which will obviously hinder the final dough's ability to rise. So... you don't want your yeast to eat all of the sugar in the dough, but you also want to give them enough time to eat a good portion of it.

Let's get nerdy. The Artisan's Yeast Treatise explains the relationship between yeast growth and temperature.

Temperature Activity
-20 C. (-4 F) Loss of Fermentation Capacity
< 20 C (68 F > 40 C (104 F) Growth Rate Significantly Reduced
20 C (68 F) - 27 C (81 F) Most Favorable Range For Yeast to Multiply
26 C (79 F) Optimum multiplication of Yeast Achieved
27 C (81 F) - 38 C (100 F) Optimum Fermentation Range
35 C (95 F) Optimum Fermentation Temperature
> 60 C (140 F) Yeast cells Die

Most refrigerators are going to maintain a temperature in the second lowest range. So, if you have time or don't want a strong flavor, a refrigerated pre-ferment is probably the way to go. Unfortunately, I had to mix the final dough some 12 hours later. I put in a fraction of the yeast called for in the recipe, added 1/10 whole wheat flour, and let the mixture sit out on my table overnight. It helped produce some delicious bread. The whole wheat, although just a fraction of the final dough, imparted a noticeable flavor, surely due to its incorporation into the biga. The bread had fantastic oven spring (better than expected) and was a great compliment to the sausages we made. I wonder if there is an algorithm to express the various time + yeast:flour ratios that would produce the same pre-fermented doughs. Oh well. Here's a picture of the bread proofing in an old (but very clean) towel.