freezers for killing museum pests

[Fewless, Gary]

We are about to purchase a "walk-in" freezer to treat museum specimens (both
plants and animals) for dermestids, etc.  I suspect the conventional wisdom
may have evolved in recent years in this area.  What temperatures are
required, and is there anything else we should consider in terms of
characteristics of the freezer?

Thanks for any help.

Gary Fewless