I have four Xperia z5 compact, now all overheating

[UGLYDOLL]

Ever since the latest update, all four of my Xperia z5 compacts (one in each color) are now running much hotter and slower. Forget taking quick photos of children... Or typing quickly on the keyboard ,
Two are from Hong Kong, two from the UK.
What's happening Sony?
(I have a 5th one from Japan, docomo version, and it's fine...most likely because they are so slow to update, so it's still on an older build number).

The 253 update on z5c needs to be fixed, I had zero heat on this phone before.
Sony, do you plan on fixing this?

[Janehal]

I totally agree, I am so disappointed with this phone, really. 

Just browsing web, facebook and check e-mails and my phone is on 44°C, I have the feeling that I could do my ironing with it. It really worries me, that it will explode or just melted inside. 

[Martin20]

As someone mention previously it could be something to do with nougat limiting the use of the cores to 4 and only at 1.5GHz. 

I was running nougat for almost 3 months and simple things like browning would make the phone very warm and I could only see 4 of the cores running. 

Since then I rolled back to mm. 253 version firmware and phone does not heat up as before and I can see all cores becoming active. Especially the ones running at 1.96GHz

So it seems maybe Sony disabled or reduced the use of the better 1.96GHz cores to maybe increase battery life but in the process settled for a warmer phone with reduced performance 

[Stewarthuk]

I have 2  Sony z5 compact phones and both get very hot.  They don't slow down or crash but they feel very uncomfortabley warm in my hand when I'm using them.  Simple Web browsing makes the back of the phone very hot. It's enough to make me buy a different phone because it is so annoying. I was trying to find a way of reducing the cpu performance when I found this thread but from reading all this I think the previous reply to mine has found the most likely cause of the problem and I hope Sony will fix it.