diff --git a/code/__HELPERS/radiation.dm b/code/__HELPERS/radiation.dm
index 8c34ce3554..d527d0ac51 100644
--- a/code/__HELPERS/radiation.dm
+++ b/code/__HELPERS/radiation.dm
@@ -13,7 +13,8 @@
 	var/list/processing_list = list(location)
 	. = list()
 	var/i = 0
-	while(i < length(processing_list))
+	var/lim = 1
+	while(i < lim)
 		var/atom/thing = processing_list[++i]
 		if(ignored_things[thing.type])
 			continue
@@ -21,6 +22,7 @@
 		if((thing.rad_flags & RAD_PROTECT_CONTENTS) || (SEND_SIGNAL(thing, COMSIG_ATOM_RAD_PROBE) & COMPONENT_BLOCK_RADIATION))
 			continue
 		processing_list += thing.contents
+		lim = processing_list.len
 
 /proc/radiation_pulse(atom/source, intensity, range_modifier, log=FALSE, can_contaminate=TRUE)
 	if(!SSradiation.can_fire)