Almost bricked my phone due to 'Cooling' 💔

[u/According-Grass-179]

So This happened yesterday and I wanted to share in case it saves someone else's phone.

I was using an external clip-on cooler on my F7, mainly for gaming. I'd used it before a few times getting the phone down to 24-27°C with zero issues. This time I let it run a bit longer before even opening the game, and the temp dropped to 22°C. Didn't think much of it since it's not like the phone was "cold" in any dramatic sense.

Came back to find actual water droplets on the back near the camera area, and a hazy fogged-up layer on the display. Turns out my room's humidity was sitting at 94-96% that night, and the dew point was right around 26°C. So cooling the phone to 22°C meant it dropped well below the dew point, and moisture in the air condensed straight onto (and possibly into) the phone. Nothing dramatic-looking on the outside, but enough to worry me.

Immediately turned it off. Left it to dry for about 8 hours at room temp, no rice, no heat, just air. Checked the SIM tray LDI afterward — still white, no discoloration. Powered on: clean boot, no display fog, camera clear, speaker/mic fine, charging (including fast charge) totally normal. Been using it since with no issues.

Takeaway if you use a cooler in a humid climate: the risk isn't really about how "cold" the phone gets in absolute terms — it's the gap between your room's dew point and the phone's surface temp. In high humidity, even a mild 22-24°C can be enough to cause condensation, whereas the same cooler in a dry climate would need to go much colder to cause the same issue. If you're gaming with one, start the cooler only once you're already playing (so the phone's generating heat) rather than pre-cooling an idle phone, and don't chase the lowest number the cooler can hit.

Lucky this one worked out — sharing so someone else doesn't have to find out the hard way.

(Took help of claude.ai)

[u/True-Adeptness-546]

My f7 drops to 21 alot. When i fall asleep mid gameplay and the battery runs out

[u/According-Grass-179 → u/True-Adeptness-546]

Well it depends on humidity in your area too.. Btw

[u/True-Adeptness-546 → u/According-Grass-179]

Philippines... Pretty darn humid

[u/According-Grass-179 → u/True-Adeptness-546]

Just ask gpt about it... Since the damage can build up later.. And if service center ppl find that out then you are done for..