It was a few years ago, at a hotel, when I had a "digital dilemma." I had my plane tickets as PDF files on my e-mail account, but no way to print them, so I was sent to the Office area, to the public access computer (with a printer attached).



The computer had a standard guest account (meaning that it would reset all settings on log-out), but the problem was the previous user. He/she didn't log out from the browser or from the Guest Account, so when I accessed Yahoo Mail, I was on his e-mail account. I verified the history and he was logged on different sites, even with his business account.
I logged out from the Guest Account, and then it hit me: what if this public computer had a keylogger installed? They will know my e-mail credentials and from there, sky is the limit!
I'm a geek, so I created a temporary e-mail account on one of the many free services and I forwarded the plane tickets from my phone to the new and "short-lived" e-mail address.

A more practical solution Now I have a very small/thin 16 GB USB drive in my wallet with a bootable Tails Linux installed via Rufus. What is Tails Linux? It is a small Linux live CD distribution that was used by Edward Snowden when he copied classified information from the NSA. The main idea is that it is a small, secure, no-logging OS.
I usually restart the public computer, and in many cases I can change the boot order device, in order to boot from the USB. By booting from USB, you make sure that no information is read from the HDD and no possible monitoring service can actually be started.
The browsing is done via secure Tor service, so there’s no need to worry. For e-mail, Tails includes IceDove (rebranded Thunderbird in Debian). Tails also include Pidgin, which is an IM chat client for Google Talk, Jabber (Facebook) and IRC.
If you want to store your configuration on Tails, you need to enable and create an encrypted Persistent Volume. If you don't like Tails, you can also use Ubuntu.