heating and battery problem

[Alayne]

My Sony Xperia Z1 has started getting really hot and battery discharges really quickly. As far as I'm aware I haven't changed anything for this to happen. Any known causes or solutions? Thanks

[Uliwooly]

Are you playing games? are you running a lot of background apps and services? auto backup with G+? Auto updating your apps? 

[Alayne]

Don't play games on it. Not really sure if things running in background but I haven't knowingly changed anything. How would I switch things off when not in use? Tried this before but not sure it worked

[Uliwooly]

settings > power management > battery > what is using your battery?