Here are some tips to help you protect your online accounts when using public computers:

1. Enable firewalls on the public computer and keep them enabled.
2. Avoid accessing sensitive accounts such as bank accounts on unsecured public computers.
3. Make sure the computer's browser and operating system are up to date and security patches applied.
4. Clear cache and history after browsing.
5. Use a VPN if available, and if not use HTTPS connections.