If you need to use a thumb or flash drive, be aware that this is how viri and malware spread. Make sure to check the thumb via a protective program before you plug it in.
Many public computers are incubators for malware. Within a day they can spread malware all over the Net.
If you have important stuff on that thumb or flash you will have to encrypt it to prevent it being poached.
The wisest thing is to get a new thumb drive and load a protector before plugging it in anywhere.
In case the computer you are using is infected, you won’t bring that disease home with you.
And by using a naked thumb/flash you won’t lose any of your precious information.