If, like me, you just visit Fuereteventura to be naked in the sunshine, then I think Feb is a bit too early. April/May are fine; Sep/Oct are fine. In summer - Jun/Jul/Aug - I prefer to go to mainland Spain as the flights are shorter.
Your comment about "too hot" is odd, because Fuerteventura usually has great cooling breezes. Invest in premium once-a-day sunscreen; I use Ultrasun or Reimann P20, in at least SPF20 or 30. It works, as long as you're scrupulously careful covering every little bit of you.
I'll be visiting Fuerte again in late April.