system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: In the house, why does heat set at 68 feel different than ac set on 68? It’s the same temperature but they feel very different!
gpt
Others have mentioned humidity which can definitely make a difference.

Another big difference is from radiant heat. On a hot day, the heat not only warms up the air, but also the walls of your home as well, and those walls radiate heat back inside. Your body absorbs radiant heat much more readily, thus why you can feel warm by a campfire on a cold evening. Your standard thermostat can't accurately account for radiant heat, so even though the air temperature may be the same, you'll feel warmer on hot days as the walls warm you up.