[CentOS] One-time reboot into alternate kernel?

Apologies if this should be well-known, but I couldn't find anything!

Situation: a system in a remote location, with no KVM, IPMI or iLO, and therefore no console access, only ssh. Multiple kernels listed in grub.conf.

Is there a way to reboot temporarily into one of the other kernels listed in grub.conf, without changing the default= line, so that a subsequent reboot will default back to the original kernel?

The problem I have is that having changed the default= line to select a kernel that doesn't boot properly, I need to have someone visit the console in order manually to select the working kernel again. I would like to avoid that situation if possible.

Thanks, Tony