Apparently I hate nitrous solenoids

[Bronze MFP]

I've aced 2 in a week. One was used and worked for me for the last month or so, the other was brand new and died 3 days after swapping it in. How in the world do I kill them so quickly? I have left the bottle open for a few hours on accident. But I did that many times before my first solenoid died. And only once this week with the new solenoid. Is the heat from my engine getting to them? What gives? Guys with nitrous, how do you keep your solenoids from giving up the ghost?