well what caused these blisters?? New sandals? If so, then let them air out first, so they will dry up. Do not wear shoes or socks or anything that could make your feet sweat. If it's poison ivy, then I suggest BLEACH. Hurts REALLY bad, but will dry them up and kill whatever oils are still in between your toes. I had poison ivy on my feet for almost 6 months. I would break the blister and pour rubbing alcohol on them, and didn't even feel it! A little old wonderful lady I worked with told me to use bleach. You could hear me screaming 3 blocks away, but by golly it WORKED!!!
KEEP IT DRY AND CLEAN
If it's from shoes though, just let them air out. I don't suggest putting anything on them. If it's from burns, call doc for some "silvadene cream". That stuff is GREAT for burns on any part of your bod. I had 2nd and 3rd degree burns on my face, and it healed up with minimal scarring with that stuff (I looked like a monster for a couple weeks, but it really does work).
Experience and common sense