diff --git a/src/simulation/Air.cpp b/src/simulation/Air.cpp
index 59a5a9e3a..f2f1f8850 100644
--- a/src/simulation/Air.cpp
+++ b/src/simulation/Air.cpp
@@ -84,7 +84,7 @@ void Air::update_airh(void)
 				{
 					if (y+j>0 && y+j<YRES/CELL-2 &&
 					        x+i>0 && x+i<XRES/CELL-2 &&
-					        !bmap_blockairh[y+j][x+i])
+					        !(bmap_blockairh[y+j][x+i]&0x8))
 						{
 						f = kernel[i+1+(j+1)*3];
 						dh += hv[y+j][x+i]*f;
@@ -110,15 +110,15 @@ void Air::update_airh(void)
 			{
 				odh = dh;
 				dh *= 1.0f - AIR_VADV;
-				dh += AIR_VADV*(1.0f-tx)*(1.0f-ty)*(bmap_blockairh[j][i] ? odh : hv[j][i]);
-				dh += AIR_VADV*tx*(1.0f-ty)*(bmap_blockairh[j][i+1] ? odh : hv[j][i+1]);
-				dh += AIR_VADV*(1.0f-tx)*ty*(bmap_blockairh[j+1][i] ? odh : hv[j+1][i]);
-				dh += AIR_VADV*tx*ty*(bmap_blockairh[j+1][i+1] ? odh : hv[j+1][i+1]);
+				dh += AIR_VADV*(1.0f-tx)*(1.0f-ty)*((bmap_blockairh[j][i]&0x8) ? odh : hv[j][i]);
+				dh += AIR_VADV*tx*(1.0f-ty)*((bmap_blockairh[j][i+1]&0x8) ? odh : hv[j][i+1]);
+				dh += AIR_VADV*(1.0f-tx)*ty*((bmap_blockairh[j+1][i]&0x8) ? odh : hv[j+1][i]);
+				dh += AIR_VADV*tx*ty*((bmap_blockairh[j+1][i+1]&0x8) ? odh : hv[j+1][i+1]);
 			}
 			if(!sim.gravityMode)
 			{ //Vertical gravity only for the time being
 				float airdiff = hv[y-1][x]-hv[y][x];
-				if(airdiff>0 && !bmap_blockairh[y-1][x])
+				if(airdiff>0 && !(bmap_blockairh[y-1][x]&0x8))
 					vy[y][x] -= airdiff/5000.0f;
 			}
 			ohv[y][x] = dh;
diff --git a/src/simulation/Simulation.cpp b/src/simulation/Simulation.cpp
index d1478c216..53145c686 100644
--- a/src/simulation/Simulation.cpp
+++ b/src/simulation/Simulation.cpp
@@ -4023,7 +4023,12 @@ void Simulation::update_particles_i(int start, int inc)
 						}
 					}
 				}
-				else parts[i].temp = restrict_flt(parts[i].temp, MIN_TEMP, MAX_TEMP);
+				else
+				{
+					if (!(air->bmap_blockairh[y/CELL][x/CELL]&0x8))
+						air->bmap_blockairh[y/CELL][x/CELL]++;
+					parts[i].temp = restrict_flt(parts[i].temp, MIN_TEMP, MAX_TEMP);
+				}
 			}
 
 			if (t==PT_LIFE)
@@ -4739,7 +4744,7 @@ void Simulation::update_particles()//doesn't update the particles themselves, bu
 				if (emap[y][x])
 					emap[y][x] --;
 				air->bmap_blockair[y][x] = (bmap[y][x]==WL_WALL || bmap[y][x]==WL_WALLELEC || (bmap[y][x]==WL_EWALL && !emap[y][x]));
-				air->bmap_blockairh[y][x] = (bmap[y][x]==WL_WALL || bmap[y][x]==WL_WALLELEC || bmap[y][x]==WL_GRAV || (bmap[y][x]==WL_EWALL && !emap[y][x]));
+				air->bmap_blockairh[y][x] = (bmap[y][x]==WL_WALL || bmap[y][x]==WL_WALLELEC || bmap[y][x]==WL_GRAV || (bmap[y][x]==WL_EWALL && !emap[y][x])) ? 0x8:0;
 			}
 		}
 	}
diff --git a/src/simulation/elements/TTAN.cpp b/src/simulation/elements/TTAN.cpp
index 3f997f7e0..248aba2a9 100644
--- a/src/simulation/elements/TTAN.cpp
+++ b/src/simulation/elements/TTAN.cpp
@@ -67,7 +67,7 @@ int Element_TTAN::update(UPDATE_FUNC_ARGS)
 
 	if(ttan>=2) {
 		sim->air->bmap_blockair[y/CELL][x/CELL] = 1;
-		sim->air->bmap_blockairh[y/CELL][x/CELL] = 1;
+		sim->air->bmap_blockairh[y/CELL][x/CELL] = 0x8;
 	}
 	return 0;
 }