A hatchling, being too cold, may be reluctant to eat. Since you mention the coolness, of the room, this could be one problem (also, as you know, they need appropriate temps for digestion).
Here are some tricks, that you can try, ~If~ a hatchling is, continuously, refusing to eat after some attempts. Also, only offer food, or try something, every 4-5 days (which you seem to be doing).
# Tease feeding can be done by lightly dancing the pink (moving it around the container as though live) or by touching it to the snake's head or body. Continuous touching/tickling, on body, is, basically, harassing the snake until the snake has had enough and strikes ... hopefully grabbing the pink. If it grabs the pink, hold ~very still~ and pray that the snake eats the pink it has in its mouth. I would never bump a hatchling's nose as this can have the opposite affect of what you are trying to accomplish (scaring the hatchling away from the pink).
# Feed at different time of the day (i.e. morning, night).
# Place hatchling, and a pink, in a well secured brown paper bag that is placed in a warm/quiet area.
# Leave pinkie in overnight.
# Place hatchling in a container, with the pink, and leave it, covered, in quiet place (you can try a dark place and a light place).
# Braining - Puncture the pinkie's head with a toothpick, squeeze out a bit of brain fluid, & smear the fluid around the pink's face/head.
# Feed live, or pre-killed, pinkie.
# Feed pinkie that is cut in half or just a pinkie's head (cut, while still frozen, then thawed).
# Wash Pinkie with a mild soap (i.e. Dawn, Ivory).
# Simply rinse the pinkie, well, with water.
# Wash & then scent.
# Scenting - You can try scenting with any of the following:
* Chicken Broth
* Dirty mouse/hamster/gerbil/etc. bedding (if you have none, try getting some from a friend, a breeder, or a pet store)
* Tuna juice (although some may have had success, I have never had any with tuna)
* Chicken skin from Kentucky Fried Chicken, or T.V. dinner, or other.
* Lizard (from live or frozen lizard.. or you can take off a part of its tail and smear the end on pinkie's face, etc., then place the tail in the pinkie's mouth)
* "Lizard scent" (A formula that is sold by some herp supply companies &/or Fishing supplies ... make sure that whichever formula you use is non-toxic ... BTW I am going to look into toxic/non-toxic thing, myself, to see if it is something I could use).
* Chick (Can purchase frozen chicks from a feed breeder)
# "Brumate" for a short period of time.
# There is, also, a method of "tube feeding" certain items that can "jump start" their hunger & feed response. Perhaps more, on that, later.
Although ... you could try putting a mouse tail (cut in half, or 1/3, to lessen length of tail) down the hatchling's throat (basically force feeding a mouse tail). Wet the tail with water, first, and start with thicker end of tail. After this, place the hatchling back into its container with a pinkie.
# If absolutely nothing, with rodents, works ... you could try a live lizard.
# Force feeding - this is a last resort and shouldn't need to be done until the passing of approx. 5 weeks since hatch date (as long as the hatchling seems to be doing okay).