+1/level to HT rolls made for survival at -HP or below, and on any HT roll where failure means instant death (due to heart failure, poison, etc.). If this bonus makes the difference between success and failure, you collapse, apparently dead (or disabled), but come to in the usual amount of time. A successful Diagnosis roll reveals the truth.
+1/level to any HT roll to avoid unconsciousness – whether as a result of injury, drugs, or ultra-tech weapons – and to resist supernatural abilities that cause unconsciousness