WordPress blog root>wp-content>Cache>temp file necessary or not?

I am working with a WordPress blog. Recently I came to know that in my site root/wp-content/cache/temp contains about 160+MB data. That is why my site hosting capacity becomes low. My question: are those temp files necessary file or not? Can I delete those temp files permanently? If I delete those files then is there any problem?
Please some one help me, it’s very urgent for me.
Thank you.

in fact The .tmp files can be deleted safely under normal circumstances – since they are usually the forgotten residue of some incomplete WordPress actions. However, it is always safer to do a local backup of the files, just in case. I already deleted the .tmp files has had no side effects, so I would assume the same for any WordPress install… Install W3 Total Cache plugin to avoid this stuffs…

Goodluck