Erythritol tetranitrate (ETN) is a well-studied homemade explosive (HME), which is known for its ability to be melt-cast at a fairly low temperature. We have observed dramatically increased handling sensitivity of ETN in the molten state, using temperature controlled drop-weight impact sensitivity measurements. Impact testing was performed using ERL Type 12 drop hammer equipment using a 2.5 kg weight, a 0.8 kg striker, an anvil and sound detection equipment. Most experiments were performed in the absence of standard grit paper, due to the elevated temperature measurements with a liquid. At room temperature, ETN exhibited an impact sensitivity of 14.7 +/- 3.4 cm, which changed to 1.0 +/- 0.6 cm in the liquid state at 65 degrees C. The change in sensitivity in the liquid state was found to be reversible upon solidification, and did not appear to correlate with temperature. Control experiments were performed in the same setup using standard explosives pentaerythritol tetranitrate (PETN) and triacetone triperoxide (TATP). This is the most sensitive material that we have been able to measure using our instrumentation, and indicates that ETN be handled with extreme caution during the melt-casting process.