Close Call

You are at three hearts, a Totem of Undying is sitting in your hotbar, and you hit a Creeper. The game only looks in your two hands, so the totem does nothing. Close Call tells you before that happens.

Where on screen: a coloured glow along the edges of the view, and one line of text just under the crosshair.

What it does

• Low health (red): at 6 health points (3 hearts) or fewer, including absorption. Pulses harder at 4 or fewer.
• Totem not in hand (gold): shown only when you are hurt, a death-protection item is in your inventory, and no hand holds one. The line reads "Totem of Undying is not in your hands". Press the hotbar key of the totem and it is gone.
• Elytra (green): while you are gliding, "Elytra: at least N s of flight left" once 30 seconds or fewer remain (pulsing at 10 or fewer). Gliding costs one durability point about every second and the game ends the glide at the last point, so N counts those; Unbreaking only makes the real flight longer, hence "at least".

Never moves items: you swap the totem into your hand yourself.

If you carry no totem, you never see the totem line. If you are not gliding, you never see the elytra line.

Result: you find out while there is still time to swap a totem into your hand, land, or wear a fresh elytra.