Dry ice

After calling around, a pound of dry ice is very small. So small in fact, transport for over an hour would melt away.

We're talking about ten/fifteen pounds for a lasting block, but it's rather inexpensive. I'll be bringing a cooler to make sure the dry ice block is nice and cozy until use.

Tom,
Yeah a 10-15 pound block would be fine. The cooler should be like this

so you don't have a CO2 assplosion.

Just out of curiosity, why are we not suppose to handle dry ice with our hands?  When I was a kid my mother worked as a researcher at a lab doing toxicology/environmental and occupational health science at Rutgers, she would often get supplies which were packaged in dry ice and let me and my siblings play with it when she was done.  Was I placed in dire peril?  Does this explain anything about me?

Well that must have been the "food grade" I was talking about, those are less likely to burn you than the regular dry ice as they are safe to use around foods and such.

Says nothing about you Noah, but plenty about your mother.
I recall cleaning grease coated parts with carbon tetracloride with my father.  Driving my bike through clouds of DDT sprayed by suburban municiplaites to control mosquitoes. No one knew squat about side effects in the 50s and 60s.

Oh, I forgot - that dog don't hunt in the 80s and 90s.

After speaking with a dry ice distributer, a bigger cooler will keep it longer.

Dry Ice can be handled in small portions for a few seconds before burning. It's a solidified version of a gas.

Also, all dry ice is food grade. Food Grade means it's clean and nice.

It'll be good.