I keep crickets in storage tubs also. I use 30 gallon tubs and I rough the sides 2/3 of the way up with sandpaper, which allows them to climb the sides up that far. This gives them more surface area and makes collecting them for feeding really easy- slide a cup up the side and a bunch jump in.
I use shelves with 12" heat tape on a thermostat. One of my sons did a growth experiment last year with cricket temperature for his science project. He found 87 to be best for growth and survival - at higher temperatures growth rate was a bit faster, but not a lot and the crickets survival rate was far lower (probably due to dehydration- since then we have worked out better ways with our fruit to keep them hydrated- we were slicing fruit into wedges and the fruit dried out rapidly. Nowadays I cut fruit in half and the skin keeps the fruit from drying so quickly inside) so maybe higher temps are now possible. But I'm happy with 87- growth rate is rapid enough.
We breed our own crickets though- so maybe if you are just buying a bunch to feed, you may not even want to heat them unless your room is very cold. THey will survive fine at room temperature- but growth rate is greatly reduced. Which is actually usually what you want anyway when you are feeding a young chameleon, otherwise your crickets may outgrow your lizard and become too large to feed. Also at lower temperatures their whole life cycle is slowed down, so they will live longer than those kept warm. Crickets don't exactly break world records for long lives (5-9 weeks or so from the time they hatch depending on temperature).
