a word about heat, if room temperature where you are is high 20's (celsius), close to 30...then you don't need a heat source.
however, as you're from up north of where *i'm* originally from (Vic, BC), i seriously doubt ambient temperatures will be good enough, unless you keep your place pretty warm normally.
i found mine only started to thrive when i brought the temps up to at least 25c.
i agree with Mr Mordax about airflow and simply dumping water on the substrate when it gets too dry.
scorpions can't climb smooth surfaces too well, so while i definitely recommend a lid of some kind, you can be pretty sure they'll stay on the bottom if you keep all climbable stuff low down.
