Good idea, Chad! I'm planning to re-drill the shelves anyway (to go lid-less), so maybe I'll try to do that.

Btw, I tried to get some aluminum tape today at Office Max, since I was in that neighborhood... they didn't have any, so I'll have to schlep to Lowe's tomorrow. And in a weird twist, the near-disaster actually helped my tubs by warming up the ambient temps! I've always had trouble keeping them high enough, since my house is super cold... but now Mona's Acu-rite is reading 80/90, so maybe the incident was a good thing.