Apple advises an immediate update to iOS 9.3.5 to protect against security vulnerabilities.
This applies to iPhones, iPads, and iPod touch devices.
- Plug your device into power andconnect to the Internet with Wi-Fi.
- Tap Settings > General > Software Update.
For instructions from Apple on how to update your device go to: https://support.apple.com/en-us/HT204204