If a Galaxy S25 Ultra has run hot since late July 2026, suspect the update before the hardware. 9to5Google reported S24 and S25 Ultra owners seeing heat and heavy battery drain after the July security update, with a background job stuck in a loop as the likely cause and WhatsApp's encrypted backup named in one case. A phone that is only warm while charging, gaming or recording video is behaving normally. Check Settings, Battery for the app at the top first; if it is cool in your hand and still empties overnight, that points to a stuck process rather than the chip.
Differential
Likely causes of “Samsung Galaxy S25 family gets hot or shows a temperature warning”, and how to tell them apart
- 1
A stuck background job after the July 2026 update
What separates it Heat and a falling battery percentage while the phone sits idle, starting in the last days of July
How to confirm Affected owners in 9to5Google's report lost roughly five to seven percent an hour on standby; Settings, Battery shows the app responsible
- 2
WhatsApp's encrypted backup running in a loop
What separates it WhatsApp sits at or near the top of the battery list although you barely used it
How to confirm Reports name the backup; let it finish on Wi-Fi with the charger connected, or pause it in WhatsApp's chat backup settings
- 3
45W wired charging with the screen on
What separates it The titanium frame feels hot along the edges while you play or browse and charge
How to confirm GSMArena lists 45W wired charging, 65 percent in 30 minutes; charge with the screen off for the first half hour
- 4
Sustained load on the Snapdragon 8 Elite
What separates it A long game, a navigation session or repeated 4K video dims the screen and slows the phone
How to confirm The chip is a 3 nm design with two 4.47 GHz cores; the phone throttles itself, which is the protection working rather than a fault
Before you touch a setting
Record this first — changing settings destroys the evidence
- The first date the heat appeared and whether it was the July 2026 update
- Whether the phone is hot while idle on Wi-Fi or only under load
- The cooling message on screen, word for word
Try in this order
0 of 5 completedUnplug it and let it cool
ReversibleRemove the charger and the case, close everything in Recents and leave the phone face up in the shade until it is cool.
Find the top battery app
ReversibleOpen Settings, Battery and look at the first three entries. One app far ahead of the rest is the stuck process.
Let or stop the WhatsApp backup
ReversibleIf WhatsApp leads, leave the phone on Wi-Fi and the charger overnight so the backup can complete, or turn the automatic backup off and on once.
Install the newest update
ReversibleReports said a later monthly patch should settle the July behavior; install whatever is waiting under Settings, Software update.
Restart and recheck after a day
ReversibleA restart clears a looping process. If the same app is on top the next evening, contact Samsung with a screenshot.
Model-specific
What is true of this model and not of its siblings
- Charging
- 45W wired (65 percent in 30 minutes), 25W Qi2 wireless and 4.5W reverse wireless on a 5000 mAh battery.
- Other models this page answers
- These steps also fit the Galaxy S25+.
Stop boundary
When this stops being a self-service repair
- !If the phone is hot with nothing running and the top battery app is not WhatsApp or another single app you can stop, contact Samsung support with the battery screen
- !If it powers off repeatedly to cool down while idle, run the Samsung Members diagnostics and book a service check
- !If the back bulges or the phone smells scorched, stop using it and go to a Samsung service center the same day
Evidence ledger
Sources behind this answer
The 32 to 95 degree Fahrenheit range and the four cooling messages.
Reports of drain and heat on S24 and S25 Ultras after the July 2026 update, and the suspected WhatsApp backup cause, published 2026-07-30.
The same reports with the workarounds shared on Samsung's forums, published 2026-07-29.
Snapdragon 8 Elite (3 nm), titanium frame, 5000 mAh, 45W wired and 25W Qi2 wireless charging.
Exact questions
Common questions
Is the S25 Ultra heating a known update problem?+
9to5Google and other outlets reported heat and drain on S24 and S25 Ultras after the July 2026 update, and the reports said Samsung had not confirmed a cause.
Is the titanium frame making it hotter?+
GSMArena lists the S25 Ultra's frame as grade 5 titanium. Titanium conducts heat more slowly than aluminum, so the glass back and the screen carry more of the warmth.
Does charging at 45W heat the phone?+
It warms it, most in the first half hour. Switching the screen off while charging and removing the case keeps the heat lower.