do higher temps of water kill bad bacteria?

My goldfish has pop eye. Not from behind mind you but the two clear
doms of the eye the cornea and lens (i think) are all swollen straight
out)

Ive raised the temp to 84 deg as per instructions - why? Does this
kill the bacteria?

I added 1/8 teaspoon epsom salts on none of sodium chloride.

I added maricyn2 for the last couple days - the red blotches are
fading. I THINK the eyes look better but its verry possable my
imagination.

I've boosted the protien in their diet and have laced a bit of kanycin
in it.

Any more ideas? Yall have been great.