memory cards in the mail - protection?

I plan to use a lot of chips while on vacation outside the US, and maybe send the cards home for safe keeping.  What protection should I use to be 99.9% confident that a chip will get home with all the data intact & ready to upload?  I expect to send them one at a time.  One at a time means no total disasters.  I hope.

Possible issues:  

crushing - possible, but protectable easily.  I mostly understand about this.

EMP (electromagnetic pulse) messing up the memory -  I _don’t_ understand how this might happen, nor how to protect against it.

Excess temperature - how high can these puppies go, in storage, anyway?

Mail theft - ship it from an official PO, trust the kindness of strangers.   OK?

What else?

If there is a FAQ for this, please point me to it.

@jay_warner wrote:

 

Possible issues:  

 

crushing - possible, but protectable easily.  I mostly understand about this.

 

Use a padded envelope and you should be ok

 

EMP (electromagnetic pulse) messing up the memory -  I _don’t_ understand how this might happen, nor how to protect against it.

 

Don’t  worry about this flash is not susceptible to EMP

 

Excess temperature - how high can these puppies go, in storage, anyway?

 

-25 to 85 c is the no operating temp for most flash so you should be fine. 

 

Mail theft - ship it from an official PO, trust the kindness of strangers.   OK?

 

I would suggest using a mail service with tracking like UPS or FEXEX and will will be fine

 

 

Wonderful!  Many thanks for the info.

Never mail your only copy of images. Making copies and mailing the copies would be okay. If you don’t plan to have a computer with you, you could copy your images at internet cafes. Or you could send them from there over the net. 

Yes, I know that rule from the days of (gasp!) film.  Also, never send them all in one pkg.  I’m going to be in Costa Rica, with people who may or may not appreciate the needs of photographers to immediately back up their work.  I’ll check around about the thought of an internet cafe.  The State Dept. web site rather discourages the idea of taking one’s own computer, unless I carry _all_ my gear everywhere I go and stay in groups of friends.