Most adhesive labels I've run across don't do so well when affixed to anything that puts off significant heat (rear of servers, external disks, some networking gear, ...).
Since manual application of an epoxy is not a solution that appeals to me, what off-the-shelf options are out there for heat-resistant labels? (Something that works in label-maker would be nice, but really I'll take anything at this point.)
You can get labels that are designed to go through laser printers. These have to handle the fuser, so the glue must have some resistance to heat. Maybe they would work for you.
I have never had a problem with P-Touch labels from a label maker coming off either cables or servers. However, I have never had servers in particular high heat environments, they have always been pretty well cooled data centers. So if you have particular high heat, you might do your best to address that (more important than labels) if you haven't already.
