heat acclimation

I have heard some people talk about significantly over-layering for a given temperature.  For example, if it's in the 60's and 70's you could be wearing an insulated winter jacket, running pants, and warm hat.

Sounds awful to me though.

edit: You might consider going a different route... think about the strategies you can use to cool yourself in the unseasonable (for you) heat.  I have had very good luck with Desoto Cool Wings + carrying a water bottle on the run.  Fill it back up with water cups from the aid stations and douse your head and shoulders in between aid stations.

There are ways to do this. Just depends on how extreme you want to get.  Layering is probably the best solution. I remember reading about someone who built a crate around their trainer and used a heater to get the temp up. Layering sounds easier and safer. Watch your electrolytes. 

The Desoto wings (and their other Skin Cooler stuff) don't work all that well in very humid environments... like Ironman Texas.  The cooling comes from the evaporative effect which is basically non-existent here in SE Texas.  I often where the items for sun protection but they don't do a darn thing to keep me cool.