Ambient temp or Wort Temp

I just read in a brewing book that fermentation is an exothermic process and that the temperature of the wort can increase as much as 10 degrees. i also confirmed this by comparing a thermoter in the room to the sticker thermometer on the side of my fermentation bucket.

So a recipe tells me to ferment at 70 degrees, do i have to make sure the room is 70 degrees or the wort that is fermenting to be 70 degrees?

Definitely the fermenter/wort temp. I had US-04 take off on me from a 65F basement ambient temp to over 73F. Estery mess.