diff --git a/src/simulation/elements/FIRE.cpp b/src/simulation/elements/FIRE.cpp
index 534507055..f9313fa97 100644
--- a/src/simulation/elements/FIRE.cpp
+++ b/src/simulation/elements/FIRE.cpp
@@ -94,7 +94,6 @@ int Element_FIRE::update(UPDATE_FUNC_ARGS)
 					(t!=PT_SPRK || (rt!=PT_RBDM && rt!=PT_LRBD && rt!=PT_INSL)) &&
 					(t!=PT_PHOT || rt!=PT_INSL) &&
 				    (rt!=PT_SPNG || parts[r>>8].life==0) &&
-					(rt!=PT_H2 || (parts[r>>8].temp < 2273.15 && sim->pv[y/CELL][x/CELL] < 50.0f)) &&
 				    sim->elements[rt].Flammable && (sim->elements[rt].Flammable + (int)(sim->pv[(y+ry)/CELL][(x+rx)/CELL]*10.0f))>(rand()%1000))
 				{
 					sim->part_change_type(r>>8,x+rx,y+ry,PT_FIRE);
diff --git a/src/simulation/elements/INVIS.cpp b/src/simulation/elements/INVIS.cpp
index 601096705..03f2d6986 100644
--- a/src/simulation/elements/INVIS.cpp
+++ b/src/simulation/elements/INVIS.cpp
@@ -42,13 +42,20 @@ Element_INVIS::Element_INVIS()
     HighTemperature = ITH;
     HighTemperatureTransition = NT;
     
-    Update = NULL;
+    Update = &Element_INVIS::update;
     Graphics = &Element_INVIS::graphics;
 }
 
+//#TPT-Directive ElementHeader Element_INVIS static int update(UPDATE_FUNC_ARGS)
+int Element_INVIS::update(UPDATE_FUNC_ARGS)
+{
+	if (sim->pv[y/CELL][x/CELL]>4.0f || sim->pv[y/CELL][x/CELL]<-4.0f)
+		parts[i].tmp = 1;
+	return 0;
+}
+
 //#TPT-Directive ElementHeader Element_INVIS static int graphics(GRAPHICS_FUNC_ARGS)
 int Element_INVIS::graphics(GRAPHICS_FUNC_ARGS)
-
 {
 	//pv[ny/CELL][nx/CELL]>4.0f || pv[ny/CELL][nx/CELL]<-4.0f
 	if(cpart->tmp)