Ander Vicario

True. From Minecraft 1.18 onward, snow golems no longer check biome temperature when placing snow.

In 1.17 (Yarn mappings), snow placement required a cold biome:

BlockPos blockPos = new BlockPos(i, j, k);
if (this.world.getBlockState(blockPos).isAir()
    && this.world.getBiome(blockPos).getTemperature(blockPos) < 0.8F
    && blockState.canPlaceAt(this.world, blockPos)) {
    this.world.setBlockState(blockPos, blockState);
}

In 26.1snapshot1 (unobfuscated), for example, this check was removed:

BlockPos snowPos = new BlockPos(xx, yy, zz);
if (this.level().getBlockState(snowPos).isAir()
    && snow.canSurvive(this.level(), snowPos)) {
    this.level().setBlockAndUpdate(snowPos, snow);
    this.level().gameEvent(GameEvent.BLOCK_PLACE, snowPos, Context.of(this, snow));
}

That's why, snow golems are able to generate snow trails in any biome, including warm biomes and dimensions like the Nether.

MC-272081

However, the snow trail should not be generated, thats the bug.

I think golems should not burn in jungle, because jungle’s temperature is 0.95 and to die it must be greater than 1.0. I think is intended.