Tmp folders

[Arp_148]

One of my project folders are filled with 119x folders named tmp_1, tmp_2, temp_3 and so on. I assume these are temporary files. 

Why are these not automatically deleted?

Can I delete them manually? 

[DanPatterson]

what is in a folder?   file extensions?   (open them in Notepad++ to see if they are text)

Were you working with rasters? images?

You can delete them manually (back them up to a USB if you are afraid of project issues),

but why not go into you projects and clear your history (Project backstage) of unused clutter regularly

[Arp_148]

The folders contains prj-files. One of the folders contains a (LAS) raster. I think all was created when I runned a mosaic process on LAS-data. 

But it concerns me I would have to delete the history line of my work just to get rid of temp-data. Is this really correct (?)