I hate people, who hates something without asking for reason first. First of all, WinSCP does not store files to temp folder always. It does it only, if you drag&drop file out of the program. If you do not use drag&drop to transfer file of if you drop it inside WinSCP (i.e. to local panel in NC-interface), file is transfered directly. The reason for all this was explained already too many times here. Just take a second to use the Search function.