I think this has become a pretty popular house rule now, but I'll outline it anyway.
- Accepting a Minor Consequence reduces Stress taken by 2.
- Accepting a Moderate Consequence reduces Stress taken by 4.
- Accepting a Severe Consequence reduces Stress taken by 6.
Let's say you have 5 Health Stress and take three 8 Stress hits. That's rough whether you're a pulp hero or not. Under SotC RAW, that would mean checking off the fifth box on your Stress track, then taking a Minor Consequence, then taking a Moderate Consequence. You have fully four of your Stress boxes clear and can still take another big hit.
Under this variation, though, with the first hit you need to take at least a Moderate Consequence; merely reducing the stress by two will still Take you Out, but reducing it by four will save you. The next hit, same thing, but now you're forced to take your Severe Consequence, reducing the stress by six. Now you have your second and fourth boxes checked, a Moderate Consequence, and a Severe Consequence. Barring something unforeseen, the next hit of 8 Stress will automatically result in being Taken Out.
Just like in SotC, "SotS" characters can take a handful of little hits without worrying too much about it, but unlike in SotC, "SotS" characters can't quite manage the bit hits as well. Note also that this makes any stunt that enables you to take an extra Consequence, like Feel The Burn, suddenly much more attractive. Also note that under certain circumstances, taking a Consequence might not be enough -- e.g., if you have all of your boxes checked and not even a Severe Consequence will prevent you from taking a point of damage, you're still going to be Taken Out.
In "Spirit of the West," I also reduced starting Stress Tracks from five to three (another Fred Hicks suggestion, I think), to make things that much deadlier, but the fantasy genre requires, in my opinion, a much greater emphasis on the variety of weapons used, which means making some do more damage than others, which means that starting with a paltry three boxes of Health Stress would result in a lot of one-shotting, which isn't exactly what I'm going for.
(Incidentally, while I'm currently bound by an NDA, I'm pleased to see that Cubicle 7's upcoming Starblazer RPG, also based on FATE 3.0, uses a similar system.)
(Also, I just want to add that the Evil Hat Wiki has some interesting ideas about incorporating weapon type into the Stress-reducing Consequences model. I don't believe I'll be using them, but they're definitely worth a look.)