Here's what I plan to use, combining Mutant: Year Zero and Coriolis rules.
DROWNING If you are underwater (by choice or not), the GM rolls basic attack dice, at your turn in the turn order and before you get to act, as an opposed roll against your Endure roll. He rolls a number of dice equal to double the number of turns you have been under water: two dice for the first turn, four dice for the second turn, and so on. As soon as you come up for air, the attacks stop. Armor has no effect.
FALLING A fall of three yards or more ending on a hard surface prompts an attack roll. The GM rolls basic dice equal to the number of meters fallen -2. Armor does not normally apply.
FIRE If you are in, or within Near Range of, a large fire, you will suffer basic attack rolls once every turn. The GM rolls the attack at your turn in the turn order, and before you get to act. He rolls a number of dice equal to double the number of turns you have been in the fire: two dice for the first turn, four dice for the second turn, and so on. As soon as you suffer 1 or more points of damage from the fire, your clothes catch fire. If you get out of the fire with your clothes on fire you continue to take one more point of damage each turn until you put out the fire. Putting out burning clothes demands a successful Move roll (you or someone else within Near Range of you may attempt the roll). Every attempt counts as an action. Armor normally has no effect.