How to rest meat but not let it get too cold?
Straight after it comes out of the pan it will usually be too hot to eat.  Regardless of resting or not, you can't fully taste things which are too hot, they need to come down to a comfortable temperature before you eat them.

Some things you can do to stop the meat being too cold when you serve it: 


You can rest the meat wrapped in foil, this will stop it from getting too cool too quickly if you are not ready to serve once its had the time to rest.
you can rest it and then warm it again before you eat it, either under a hot grill for a little, or in an oven.
serve it with a hot sauce which will warm the meat
serve it on a warmed plate which will stop it cooling more too quickly on the table


Although I think you are worrying too much about nothing IMHO.  Even once rested the meat will still be at a good temperature, especially as you have not cut it yet and most of the heat will be retained in the middle of the meat.