For my away team, it seems random. I gave my tactical officer a hypo and she used it right away...when she had full health and we were out of combat. I gave them all tribbles to speed out of combat healing, but they don't always use them.

One ground mission was extremely difficult for my team and upon respawning for the nth time, I decided to load them up with hypos, shield regens and power devices. We managed to live a wee bit longer before the Klingon Swordmaster and Dahiro Master made mashed potatoes out of us. 2200 total hitpoints on one enemy...bah.

When they get knocked out and I revive them, the damn tribbles are still there.

My last rough ground mission I was the first knocked out...this insane Klingon Dahiro Master sliced and diced almost of us into dog food. It ended up one on one and my engineer finally fried him. I kept clicking 'call for help' but was dismayed to see they were stuck on a box and couldn't walk around it.