I would think it would melt. Yahoo ziplock and see what they say.
I just found this:
Shane Steinkamp wrote:
>>I can't believe I haven't tried this yet, but will a ziplock melt if
>>boiling water is poured into it? I usually just eat out of the pot in
>>which I'm cooking, but pouring the water into the ziplock would prevent
>>the cleaning of a pot after dinner. Someone alluded to this earlier.
>>What is the scoop?
I did this just a couple of weeks ago. I got the kind that will stand
upright on their own (for ease of water pouring), put the rice in one
bag and the yummy retort packaged indian food in another. Poured the
water in, wrapped them in my fleece jacket, and waited five minutes.
I was using Glad 1 quart Stand & Zip bags. The box specifies
they can be used in a microwave so I felt reasonably safe, healthwise,
putting boiling water in them. I haven't checked out the Ziplock
After I finished eating (the bag having been left to sit on the frozen
ground in the meantime) I found that the water still in the indian food
bag was still plenty warm enough to wash stuff with. It felt heavenly
on my hands. :)
The bags have cup gradation markings on them, which is handy.