Detection of narrow (δλ < 0.5 Å) absorption features in C IV at λλ1548 and 1550 have been made in the spectra of 4 late B dwarfs within 200 pc of the sun; the Si IV doublet at λλ1393 and 1403 shows up in two of them. The authors argue that it is difficult to account for the strengths, widths, shapes, and C IV/Si IV ratios in terms consistent with a circumstellar origin except possibly for an asymmetric C IV component in one star (HD 185037). The most probable source is "semi-torrid" gas (cf. Bruhweiler et al. 1980) in the 50,000K range forming the interfaces between cooler H I clouds and the ambient medium at coronal temperatures. The technique, using late B rapid rotators, is useful for LISM probing of this kind.