Just make sure to get a goldenrod for inside your safe and you should be fine.
WV it looks like the Goldenrod works by keeping the inside of the safe warmer than the outside temperature. I live in Phoenix Arizona and I will be keeping the safe in the garage. For at least 4 months a year the temperature is always above 100 degrees. I'm not sure if I want something making it even hotter in the safe!

How about the non-electric dehumidifiers?