Is there any particular stems you mean?
Every Dynavap stem I've tried the tempest on was totally unusable for me, they can't deal with the heat from the head. I wasn't expecting them to work given the extra heat that comes through the native stem, but I wanted to try some anyway.
Would be interested to hear how a simrell copes if you use one of those.
I remember my older simrell being mega hot as well after back to back Dynavap bowls.
I think what
@General Disaster was saying about the outer getting hot because it's doing the work inside is definitely right, the heat needs to go somewhere.
A few days after I got my tempest, I swapped the head with the Dynavap tip on my revolve gen 2.
The tempest head on the revolve gen 2 with titanium sleeve, it still vapes fine, but the vapor felt warmer on the back of my throat, but the titanium sleeve got so hot that using it wasn't much fun as it was enough to draw attention.
Running my main Dynavap tip+armoured cap+CCD spacer (for extra mass) on the tempest stem with heat shield etc, 3/4 back to back bowls and it managed fine, it was warm but it wasn't uncomfortable.To
The wooden sleeves do make a difference but I'd rather the heat was on the outside than in the vapor.