Xia is full of opportunities for hotshot stunt pilots: there are plenty of nebulas and asteroid belts to whiz about in, but it's a risky maneuver. You roll a d20, and if the result is from 1 to 10, you take that much damage (or, in a nebula, lose that much Energy). The rules call out that shields can protect you from these hazards, but it's unclear when you must place arming tokens on your shields in order to do this.
If you must place the arming tokens before entering the field, then there's a 50% chance that you wasted both energy and actions. This is a very steep cost, considering that the most common use of shields, defending against enemy fire, doesn't cost you an arming token and has a guaranteed benefit. (Or rather, you don't need to save an arming token from last turn, and you're allowed to re-arm immediately after the attack; it costs energy, but not actions.)
So do you need to activate shields before rolling for the result of entering hazardous spaces, or can you do it afterward?