diff --git a/code/modules/surgery/organs/internal/lungs/_lungs.dm b/code/modules/surgery/organs/internal/lungs/_lungs.dm
index db8a0b6e3616..3add69de08dc 100644
--- a/code/modules/surgery/organs/internal/lungs/_lungs.dm
+++ b/code/modules/surgery/organs/internal/lungs/_lungs.dm
@@ -715,7 +715,7 @@
 
 	src.last_partial_pressures = partial_pressures
 
-	if(breath.total_moles() > 0)
+	if(breath.total_moles() + breath_out.total_moles() > 0)
 		handle_breath_temperature(breath, breather)
 		// Merge breath_out into breath. They're kept seprerate before now to ensure stupid like, order of operations shit doesn't happen
 		// But that time has passed