I would be a lot more worried about the Clinton-Administration DME than the yeast nutrient. The nutrients contain no live elements and are not affected by heat. Most people add their nutrient 10 minutes before flameout (or when you add your DME when brewing up a starter).
You will know in a few days how your DME is going, but I think it will probably be fine as well. It may have some funky, stale flavors, but you are just making a starter. I am sure the yeast will eat it up just fine.
Crooked Horn Brewing Co.
BREWtality 2 Build Thread
"Always remember that I have taken more out of alcohol than alcohol has taken out of me."
"No soldier can fight unless he is properly fed on beef and beer."
"Make sure that the beer - four pints a week - goes to the troops under fire before any of the parties in the rear get a drop."
-Winston Churchill----brilliant man