While at home, you can keep them on if you need to, but when you leave home, turn both off. When your phone has Wi-Fi or Bluetooth on while you are outside, it is a location device that all WIFI’s and Bluetooths around will detect. Even if you don’t connect to them, those WIFI’s and Bluetooths will know your device name and unique identification and even your apps and your phone will keep a record of where you are by triangulating the nearby WIFI’s or Bluetooth signals.
Android
The previous option to Turn Wi-Fi off when screen is off for Android phones is not available anymore.
Simply turn your wireless connections only when you need them, then turn them off when leaving the house or a known place.
You can either slide your finger from the TOP to display the shortcuts and turn off Wi-Fi, Bluetooth and NFC, these are the icons you are looking for, make sure they are off.
 |  |  |  |  |
| WiFi On | WiFi Off | Bluetooth | NFC | Mobile Data |
Or go to Settings and look for Connections where you will be able to turn them off by clicking on the toggle icon:
 |  |
| Option is On | Option is Off |