Hi Al Nashi,
there are a few threads dealing with that.
For the first it depends on which laptop you are using and if this has a good cooling solution inside (e.g. IBM is/was aware of a heat problem of their pcmcia slot in the Thinkpad series).
But be aware of that there had been problems in badly designed laptops using one pcmcia daq card. Trying two of them directly over one another could be a problem. Please try to extra cool the laptop (if possible) when using two cards...
greets!