I brought my Iphone 7 in the hotub and stupidly submerged it and now it won't turn on. How much will it cost to fix?

While I was with a friend, I brought my Iphone 7 in the hotub with me. I fully submerged it countless times underwater thinking that nothing would happen. At first, my phone was fine, it was working perfectly. But after I let my phone die it just stopped working. I don't know if this is because the hot temperature of the water, or because the moister but I just want to know if there's any way I can fix this without having to take it to the apple store. And if it needs to be fixed how much will it cost?

First, get a ziplock bag filled with rice and leave your phone inside of it for 24-48 hours. Rice absorbs water, so just leave your phone in there for a chance to save it. As for the fixing part, it will probably cost more money to fix it than to get a new one, so I suggest looking for places that sell used iPhones. Maybe you'll get one with a good price. Fixing it would probably cost more than a hundred dollars.

Very likely the cost of of a new iPhone 7… Electronic gadgets hate water, as water is an excellent conductor of electricity, and once it gets inside it forms an electrical bridge between circuits on the board and causes a short circuit that fries everything.

The only way to fix it after exposure to water is to stick it in a hot airing cupboard for a couple of weeks to dry everything out, and if you press any buttons before that, then you've very likely completely knackered it beyond repair.

Apparently you can also open it up and wipe it down with Isopropyl Alcohol, but if it's already quit working it's probably too late for that.
http://www.smartmobilephonesolutions.com/content/using-alcohol-phone-dropped-in-water

The rice bag trick is an urban myth.
https://smartphones.gadgethacks.com/how-to/myth-debunked-uncooked-rice-isnt-best-way-save-your-water-damaged-phone-0154799/

$20,000,000,000,000.00USD