Way back in the day when I started diving, everyone dove US Navy tables or derivatives and as such had to accommodate limited safety margin built into them. As a result divers:
1) Avoided square profiles,
2) Used the next deepest depth, or
3) the next greatest time and
4) on a hard working or cold water dive, used the next deepest depth and next longest time.
With the use of doppler ultra sound, the recreational versions of the US Navy tables got shorter "doppler" no decompression limits.
With computers things changed and multilevel diving and continuous real time calculations became the norm and that changed the need for next deepest/longest depths and times.
Some computers take into account water temperature but that's pretty pointless as it has no way of knowing whether a diver is in a 3mm shorty or a drysuit with really heavy undergarments, so without some sort of anal probe (never a great seller) it will not know if you are cold or not.
Some computers, like the Sol also consider heart rate, and breathing rate based on the assumption that this will increase on-gassing. Frankly, I'm not a real believer and I prefer to be the decision maker when it comes to adding more decompression time. One selling point for the Luna is that it has less crap on it than the Sol.
The Luna does let you set the conservatism of the bubble model it uses and it will add some time for rapid ascents, but in general don't worry about shortening the NDLs in cold water as if you stay within the limits of the computer and do a reasonable safety stop you should be fine.
I love my Luna, I was just curious.
