Feeling if held items are particularly hot or cold in examine description (#34875)

* Optimize handle_reactions().

* .

* Little bit faster.

* Faster.

* Bit faster.

* .

* Move these earlier.

* Faster.

* Faster.

* Faster.

* Update Chemistry-Holder.dm

* Remove redundant checks.

* Skip null check.

* Sensing if something is hot by touch.

* Update Chemistry-Holder.dm

* Update items.dm

* Update human_defense.dm

don't need these here

* Update shock.dm

* Update items.dm

* Update items.dm

* Update items.dm

---------

Co-authored-by: Hinaichigo <hinaichigo@github.com>

code/modules/mob/living/carbon/human/human_defense.dm

@@ -593,4 +593,4 @@ emp_act
 		return PACID
 
 /mob/living/carbon/human/beam_defense(var/obj/effect/beam/B)
-	return is_wearing_item(/obj/item/clothing/suit/reticulatedvest) ? 0.4 : 1
+	return is_wearing_item(/obj/item/clothing/suit/reticulatedvest) ? 0.4 : 1

code/modules/mob/living/carbon/shock.dm

@@ -46,10 +46,9 @@
 /mob/living/carbon/proc/handle_shock() //Currently only used for humans
 	update_pain_level()
 
-
-/mob/living/carbon/proc/total_painkillers()
+/mob/living/proc/total_painkillers()
 	for(var/datum/reagent/R in reagents.reagent_list)
 		. += R.pain_resistance
 
-/mob/living/carbon/proc/has_painkillers()
+/mob/living/proc/has_painkillers()
 	return total_painkillers() > 0