Instant cold packs are now being used to make "crystal meth" or methamphetamine

Instant cold packs are now being used to make "crystal meth" or methamphetamine.

Meth cooks usually use anhydrous ammonia...a farm fertilizer. But it often must be stolen and can be tough to find in the winter.

So they're making their own from ammonium nitrate...the ingredient in most instant cold packs (Nexcare, etc).