Shock initiation is one of the most important properties of energetic materials, which must transition to detonation exactly as intended when intentionally shocked and not detonate when accidentally shocked. The development of Manganin pressure gauges that are placed inside the explosive charge and record the buildup of pressure upon shock impact has greatly increased the knowledge of these reactive flows. This experimental data, together with similar data from electromagnetic particle velocity gauges, has allowed us to formulate the Ignition and Growth model of shock initiation and detonation in hydrodynamic computer codes for predictions of shock initiation scenarios that cannot be tested experimentally. An important problem in shock initiation of solid explosives is the change in sensitivity that occurs upon heating (or cooling). Experimental Manganin pressure gauge records and the corresponding Ignition and Growth model calculations are presented for two solid explosives, LX-17 [92.5% triaminotrinitrobenzene (TATB) with 7.5% Kel-F binder] and LX-04 [85% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX) with 15% Viton binder] at several initial temperatures.Key words: detonation, shock initiation at different initial temperatures, energetic materials, plastic-bonded explosives, modeling of initiation, LX-04, LX-17.Energetic materials (EMs) are widely used in both industrial applications and at defense oriented establishments. Initiation of such materials is of particular interest for reason of safety as well as for control of the desired effect during their application. Energetic materials exist in gaseous state as well as condensed phase in homogeneous form, such as liquids and pastes, and in heterogeneous form, such as solid compositions consisting of granular mixtures of energetic materials with either energetic or inert binders.There are various possible ways to initiate energetic materials. Gaseous mixtures, such as hydrogen and oxygen, can easily be initiated with a spark, a heating element or an open flame. Condensed EM can be initiated by either mechanical or thermal heating or by any other kind of dynamic loading such as shock loading. Of all the initiation mechanisms, shock loading lends itself to the best quantitative analysis of the phenomenon be-