No it's not dead! Depending on the gravity of the beer and how well you aerated the wort your fermentation may take up to 36 hours to begin actively fermenting. The first phase of fermentation is known as the lag time when the yeast consume the available O2 to grow, if the wort was not adequately aerated this phase can take a bit of time. Relax and worry about getting your temperature down prior to active fermentation. Assuming you brewed an ale you will want to ferment in the mid 60's.