I did my first brick on Monday. Rode 40 miles and felt strong. Then I ran 3 miles---it was quite warm for December (in the 60s) and although I was wearing running shorts & a s/s t-shirt, I got a bit overheated. The run was hard but I wouldn't let myself walk. Looking back, I think I was dehydrated a bit, so I'll have to remember to get more fluids in next time.