[General Topics] Sleepsy:
I know that I can't be the only one to have discovered/thought of this. However, I couldn't find anything online about it. I figured this could help others.

DESCRIPTION: Results

DIY Heat sink cushion keeps my Galaxy S8 as 24/7 WIFI Hotspot [20-30gb/day] & using it <90°F [screen on], <80°F [screen off].

Instant cooling for overheated phones:

When placing 99°F phone on the cushion, it dropped 3°F within 2-3 seconds; -5°F <10 seconds; -10°F <1min (Was much faster, but I didn't time the last one))

I figure this might help some people out, as many developers leave the phone on their desk, running CPU/etc. intensive activities. Or even for playing games.

On a side note,

I tried water, but for some reason it always tended to leak. So, I stuck with dish soap. I keep 2 of them handy, and leave the other on a cool surface, once warm (I use the marble floor, but you could use any metal or glass surface also. Bonus points if you use it while on that surface)

SETUP: Feel Free to Improvise

☻Quart Ziplock Freezer Bags. Can use different sizes if you choose. Regular (thin) ziplock bags are likely to leak.

☻Fill with 1/2" to 1" thick with dish soap, when laying on it's side. Water leaked, when I tried.

☻Removing bubbles is important, so I submerge them in water, to evacuate the air when sealing it.

☻Double bag, otherwise you're asking for it to leak. Although, if it does... it's just soap.

☻Keep 2 bags, so you always have a cool (room temperature) one handy.

☻Cool by placing on a stone/ metal/ glass surface, when not in use. Fridge is another option, if needed.

☻Place phone, preferably without case, on top of the dish soap ziplock bag, and enjoy a great heat sink.

BACKGROUND STORY:

I used to use a cheap Galaxy S7 Edge SM-935V ($40 on ebay/cracked glass/good LED,) running FoxiFi on Android 6.01, as my home wifi. As, I have a VZW gUDP, and the speeds used to be 120mbps/60mbps, which was faster than cable internet in my area. This in turn, powered my cable TV streaming via chromecast, etc., using 20-30gb/day. I ran my Galaxy S8 SM-G950U off the wifi, and would swap the sim when leaving the house.

My phone would always run super hot, running wifi hotspot 24/7, as home internet. I used to bloat batteries like crazy. Until one day, I placed my phone on top of a double ziplocked bag, filled with dish soap (I personally use 1/2" and 1" thick, in quart ziplock freezer bags). I had it, as I freeze them, and use as cold packs for my back. The phone experiment, was when the bag was already room temperature. I was amazed, the phone stayed relatively cool, <90 degrees Fahrenheit the whole time.

I finally upgraded the S8 SM-950U to SM-G950U1 firmware a few months ago, which allowed me to use the hotspot for free. And without having to do the simcard trick (removing Sim, then going to the hotspot menu, inserting it and activating the hotspot 1-2 seconds later) As it's my primary phone, I really don't want to damage the battery, and have since gotten accustomed to placing it on the ziplocked dishsoap, whenever it hits 93 degrees (app notifies me) or it's being charged. I'm able to use the phone while doing so, unlike the methods of placing the phone WITHIN a ziplock bag, and submerging it in water.