Another way to feel the heat without the oil mess, is to place your hand on the radiator. Since the blockheater is plugged into the waterjackets in the block, the water will heat up and start circulating on it's own. Depending on how cold it is, plugging my heater in usually gets the temp. a little above 40C.
1994 MB E320 Coupe (199,500 mi)
1992 MB 190E 2.6 (173,000 mi)
1983 Porsche 911SC (148,000 mi)
2004 Volvo V70 2.5T (198,000 mi)
President of CT/Westchester Section