Inside my home, gesture control works perfectly.  Outside, it keeps loosing connection to my palm.  Lights will turn green for a few seconds and then go back to blinking yellow.  I live in Arizona and its hot and sunny.  Any chance the heat or sun causes GC to fail?

I don't know if heat has any effect on gesture control but they do recommend wearing dark clothing to help the Spark respond to gestures.

I'm in Arizona - and the 115+ temperatures really do limit the times that you can be outside flying.  I've tried the gesture controls quite a few times - and in my own experience, they work fine for palm take off, palm landing, using the "frame" gesture to have it take photos of you, and the "beckon" gesture to come back for the palm landing.  I was somewhat frustrated in that when "waving" it away - it doesn't go more than about 20 yards away - and sometimes it's hard to get it to go that far.  I became frustrated, and started using the Remote Controller with an iPad for all my recent flights - and am enjoying that much more, gaining confidence - and sometimes frustration, in that the QuickShot modes seem to be limited to the "rocket", "circle", and the follow me modes.   Still can't get the "dronie" or "helix" to do much, other than watch the drone fly quickly away - before I take back control with the Controller.  The batteries themselves have a "rated" temperature window of less than 100 degrees, and while I've seen no damage from the heat, I am wary of it - as well as protective of myself.  Happy Flying.

I believe the set of videos on GC (see above) states dark clothes absorb the IR signal from the drone.  You are supposed to wear light clothes that contrast with your background.

i bet it works better when you have sun in front of you and behind the spark.

I tried gesture control for the first time the other day right after sunset. It worked fine for takeoff and gestures but as soon as I waved it away it rose up and away from me and lost track. I had to connect with the phone to bring it back down, I blame the low light for it and will try it again in better conditions.