Proto-MSA

*ḳṣm - to be cold (Kogan 2015:542)

The origin is uncertain.

Mehri
ḳāṣəm - coldness; cold (ML 240)
“Nearly all attestations of ḳāṣəm refer to substances which become cold after being hot or warm, which correlates nicely with the meaning of the cognate root in Soqotri” (For detailed discussion see Kogan 2015:492-493).
Jibbali
ḳéṣəm - to go cold (JL 152)