Funny. I JUST got a Smoktech Fury-S a few days ago and I'm having the EXACT same problem. Google search reveals that we're not the only ones.
In fact I just registered on this forum to ask this same question.
I'm running a 0.8ohm build, and Panasonic CGR18650CH batteries. This happens across multiple batteries. When I feel the switch get hot I pop the battery out in a hurry, but the battery itself is never hot. The switch isn't getting super hot, but enough to make me take notice and make me worry a bit. I took it into the shop where I bought it today and the lady working there said it's normal - but I don't buy it.
So - if I'm reading 0.8 ohms across my atty, I don't have a short, right? Or is there clearly a short somewhere else in the device, and how do I test it? I'm considering returning this device. I'd definitely welcome recommendations for a new mechanical mod if I can't figure out what else is wrong...
Thank you. I'll get out some alcohol and lint free towel and let you know how it goes.It means that the switch's resistance is too high, so in a way, it's acting like another coil. Clean ALL the threads. If you can, disassemble the switch and clean it up too.
Thank you. I'll get out some alcohol and lint free towel and let you know how it goes.

PS. something specific I notice about the heat is that it isn't the switch that is heating up directly, its the inner "ring" inside the switch. The resistance across the switch is about 0.5 ohms. (I think... if I'm testing it right)
If it IS right (and it very well could be based on the fact that it gets hot) that means there's something wrong with the switch. 0.5 ohms is WAY too high a resistance for a switch - if you have an atomizer at 0.5 ohms, HALF the power your battery is putting out is getting wasted heating the switch, and that's NOT a good thing.
Honestly, I would not use that mod until you get the issue sorted out, something inside that switch is making a poor electrical contact.
This is sounding right to me. Here's why: I've noticed that on occasion that it gets quite hot, my vapor production drops way off. The first time it happened, I thought I was imagining things. But occasionally I'll get a fantastic pull and notice that it didn't heat up on me.
Also, this switch is already getting "stuck" in the on position occasionally.
There's no way to disassemble this switch so far as I can tell...
Would the best course of action try to be to return this device? I'm really worried that the shop is going to give me a hassle because the seller said "it's normal"... but from what I'm reading here, it can't possibly be good.
Ok I'll take it in tomorrow and see what they say. Thanks for all the help.
During my google searching I found a thread where some others were talking about a similar issue over in APV discussion, I might add to that thread and see if anyone found a solution. (Oops, I can't. Looks like I'm locked out.)
Thanks again. Glad I signed up on this forum. Very helpful.