Entering certain nether portals causes burning

Upon enter a nether portal that I created within the End Dungeon, I am ported to another nether portal which I created to pair with the first one, at nether coordinates 192/28/65. When I arrive in the nether, I am immediately set on fire, as if stepping into flames or lava. I'd initially thought it was related to netherrack being immediately behind the portal animation, but upon clearing blocks the issue remains persistent. I would attach a video clip I took, but the file is too large.