Water blisters-pop them and you'll feel alot better.
In the Army we used to take a pin, heat it up with a lighter to sterilize it, then poke the side of the blister. You can squeeze them so all the fluid is on one side then poke the skin where the fluid is. Just want to get under the skin. The water will drain out...can squeeze out any extra water too.
Should feel alot better as the pressure will be released.
Can also take moleskin, cut it out in a doughnut or ring shape and put it over the blister with the blister in the middle and the ring of moleskin around the blister. Should cushion it.
Drugstores and such usually sell the moleskin already in the doughnut shapes.
Bring a needle/pin with and moleskin on your hunt too, just in case. We always had some with us in the field or or road march for when "the dogs start barking" as we called it.