diff --git a/code/modules/events/cat_surgeon.dm b/code/modules/events/cat_surgeon.dm
index 2d5651b9b1..76c72a7ec2 100644
--- a/code/modules/events/cat_surgeon.dm
+++ b/code/modules/events/cat_surgeon.dm
@@ -10,8 +10,28 @@
 
 /datum/round_event/cat_surgeon/start()
     var/list/spawn_locs = list()
+    var/list/unsafe_spawn_locs = list()
     for(var/X in GLOB.xeno_spawn)
-        spawn_locs += X
+        if(!isfloorturf(X))
+            unsafe_spawn_locs += X
+            continue
+        var/turf/open/floor/F = X
+        var/datum/gas_mixture/A = F.air
+        var/oxy_moles = A.get_moles(GAS_O2)
+        if((oxy_moles < 16 || oxy_moles > 50) || A.get_moles(GAS_PLASMA) || A.get_moles(GAS_CO2) >= 10)
+            unsafe_spawn_locs += F
+            continue
+        if((A.return_temperature() <= 270) || (A.return_temperature() >= 360))
+            unsafe_spawn_locs += F
+            continue
+        var/pressure = A.return_pressure()
+        if((pressure <= 20) || (pressure >= 550))
+            unsafe_spawn_locs += F
+            continue
+        spawn_locs += F
+
+    if(!spawn_locs.len)
+        spawn_locs += unsafe_spawn_locs
 
     if(!spawn_locs.len)
         message_admins("No valid spawn locations found, aborting...")