You make a valid point - circumstances do dictate actions. Usually, for instance, avalanches are not much of an issue in southern Arizona, whereas excessive daytime heat may be an issue; night operations sometimes offer advantages in that regard.

Our night ops were mostly in the initial stages of a search or rescue when time was more likely to be of essence. This was doubly true when extreme weather conditions were present. In protracted efforts, we generally slipped into more of an 8 to 5 mode.

SAR people have missed clues during daylight, as well as at night. If the missing person builds a fire at night, finding becomes very likely, more so than in the daytime.

I would far rather track at night than during the daytime. Sunlight, especially when high overhead, washes out details which are easily visible at night with a properly angled light. I once tracked a lady (blonde over blue, 125 pounds) for about eight miles down a trail, finally meeting her about 4:30 AM. "You hiked all night just to find me?" she inquired when we met. "Aw, shucks, mam'm; just doin' my job" I mumbled, or something to that effect.

The vast majority of our operations either began at night, or extended into darkness (80-85% perhaps). To be fully SAR capable, you must be able to operate at night; you must also be aware of conditions and adapt and adjust to them as circumstances dictate.

One final note. Night capability is very handy when you must operate in caves or mines.