As a system adminstrator you should know that no user program can cause the problem you describe. Its a problem in the operating system software. However, you can fix the problem of large files by setting the TMPDIR environment variable to a partition with plenty of disk space, limiting the size of the image you process with imagemagick (e.g. reject any image greater than 2048 x 2048 pixels), or by setting the MAGICK_MAP_LIMIT and MAGICK_DISK_LIMIT environment variables. ImageMagick exits if MAGICK_DISK_LIMIT is exceeded. Try, for example, a MAGICK_MAP_LIMIT of 256 and MAGICK_DISK_LIMIT of 1. The map limit is in mega-bytes and the disk limit is in gigabytes. You can also sets these limits from an ImageMagick API.
Also, note a Q8 version of ImageMagick uses 100% less resources than the Q16 version.