Fix according to MarkvA's comments

code/game/machinery/poolcontroller.dm

@@ -105,13 +105,18 @@
 		ui.open()
 
 /obj/machinery/poolcontroller/Topic(href, href_list)
+	if(..())	return 1
 
 	switch(href_list["temp"])
 		if("Scalding")
+			if(!src.emagged)
+				return 0
 			src.temperature = "scalding"
 			src.temperaturecolor = "#FF0000"
 			miston()
 		if("Frigid")
+			if(!src.emagged)
+				return 0
 			src.temperature = "frigid"
 			src.temperaturecolor = "#00CCCC"
 			mistoff()

nano/templates/poolcontroller.tmpl

@@ -15,7 +15,7 @@ Used In File(s): \code\game\machinery\poolcontroller.dm
 		{{if data.emagged}}
 			<b><font color='red'>WARNING: SAFE MODE OVERRIDE</font></b>
 		{{else}}
-			<b><font color='green'>Safties Nominal</font></b>
+			<b><font color='green'>Safeties Nominal</font></b>
 		{{/if}}
 	</div>
 </div>