Welcome to the AHA Forum saberhagen.
A good rule of thumb for fermenting beer is low 60's for ales and upper 40's for lagers but it is also depenent upon yeast strain, OG, and beer style. For a dark ale, I like to pitch in the low sixties and allow the wort to slowly rise to about 65-68 tops. The fermentation is one of the most important parts of the brewing process and fermentation control is vital. Fermenting your beer in the 70's will allow for some excess ester formation and some higher level alcohol production as well. You will make beer but on th next batch follow the rules I laid out and your beer will be much better.