diff --git a/src/simulation/tools/Air.cpp b/src/simulation/tools/Air.cpp
index b7b135132..9fd7f7967 100644
--- a/src/simulation/tools/Air.cpp
+++ b/src/simulation/tools/Air.cpp
@@ -12,6 +12,10 @@ Tool_Air::Tool_Air()
 int Tool_Air::Perform(Simulation * sim, Particle * cpart, int x, int y, float strength)
 {
 	sim->air->pv[y/CELL][x/CELL] += 0.03f*strength;
+	if(sim->air->pv[y/CELL][x/CELL] > 256.0f)
+		sim->air->pv[y/CELL][x/CELL] = 256.0f;
+	if(sim->air->pv[y/CELL][x/CELL] < -256.0f)
+		sim->air->pv[y/CELL][x/CELL] = -256.0f;
 	return 1;
 }
 
diff --git a/src/simulation/tools/Cool.cpp b/src/simulation/tools/Cool.cpp
index 12a6b2800..b1b57b170 100644
--- a/src/simulation/tools/Cool.cpp
+++ b/src/simulation/tools/Cool.cpp
@@ -13,6 +13,10 @@ int Tool_Cool::Perform(Simulation * sim, Particle * cpart, int x, int y, float s
 	if(!cpart)
 		return 0;
 	cpart->temp -= strength;
+	if(cpart->temp > MAX_TEMP)
+		cpart->temp = MAX_TEMP;
+	if(cpart->temp < 0)
+		cpart->temp = 0;
 	return 1;
 }
 
diff --git a/src/simulation/tools/Heat.cpp b/src/simulation/tools/Heat.cpp
index a2c500c9c..f28274cad 100644
--- a/src/simulation/tools/Heat.cpp
+++ b/src/simulation/tools/Heat.cpp
@@ -13,6 +13,10 @@ int Tool_Heat::Perform(Simulation * sim, Particle * cpart, int x, int y, float s
 	if(!cpart)
 		return 0;
 	cpart->temp += strength;
+	if(cpart->temp > MAX_TEMP)
+		cpart->temp = MAX_TEMP;
+	if(cpart->temp < 0)
+		cpart->temp = 0;
 	return 1;
 }
 
diff --git a/src/simulation/tools/Vac.cpp b/src/simulation/tools/Vac.cpp
index 2777f7501..aa319e2c6 100644
--- a/src/simulation/tools/Vac.cpp
+++ b/src/simulation/tools/Vac.cpp
@@ -12,6 +12,10 @@ Tool_Vac::Tool_Vac()
 int Tool_Vac::Perform(Simulation * sim, Particle * cpart, int x, int y, float strength)
 {
 	sim->air->pv[y/CELL][x/CELL] -= 0.03f*strength;
+	if(sim->air->pv[y/CELL][x/CELL] > 256.0f)
+		sim->air->pv[y/CELL][x/CELL] = 256.0f;
+	if(sim->air->pv[y/CELL][x/CELL] < -256.0f)
+		sim->air->pv[y/CELL][x/CELL] = -256.0f;
 	return 1;
 }