public static final float HEAT_STEP = 0.05f;

   public float getHeatLevel() {
        return heat / getMaxHeat();
    }

    private void increaseHeat(int numTanks) {
        float heatLevel = getHeatLevel();
        float change = Steam.HEAT_STEP;
        if (heatLevel < 0.25f) {
            change += Steam.HEAT_STEP;
        }
        if (heatLevel < 0.5f) {
            change += Steam.HEAT_STEP;
        }
        if (heatLevel < 0.75f) {
            change += Steam.HEAT_STEP;
        }
        change /= numTanks;
        heat += change;
        heat = Math.min(heat, getMaxHeat());
    }

    private void reduceHeat(int numTanks) {
        float heatLevel = getHeatLevel();
        float change = Steam.HEAT_STEP;
        if (heatLevel > 0.25f) {
            change += Steam.HEAT_STEP;
        }
        if (heatLevel > 0.5f) {
            change += Steam.HEAT_STEP;
        }
        if (heatLevel > 0.75f) {
            change += Steam.HEAT_STEP;
        }
        change /= numTanks;
        heat -= change;
        heat = Math.max(heat, Steam.COLD_TEMP);
    }