If damage dealt by a hot source you control is being divided or assigned among multiple permanents an opponent controls or among an opponent and one or more permanents they control, divide the original amount before adding 1. For example, if you attack with a 5/5 hot creature with trample and your opponent blocks with a 2/2 creature, you can assign 2 damage to the blocker and 3 damage to the defending player. These amounts are then modified to 3 and 4, respectively.

The additional 1 damage is dealt by the same source as the original source of damage. The damage isn’t dealt by Don’t Try This at Home unless it is the original source of damage. Note that while it is the source of damage for its activated ability, it won’t be on the battlefield as that ability resolves and its first ability won’t increase the damage it deals. (However, if it’s still in the graveyard at that time, it will count itself, as it is very much a hot card.)

Hot refers to temperature, not physical attractiveness, internet trendiness, or any other non-temperature-related meanings. Hot items may include objects that are traditionally hot, such as flames or the sun, or they may also include objects that are shown to be hot, such as a magic sword melting the item it’s touching.

Don’t Try This at Home has received a minor update to its rules text. The first ability is a replacement effect, not a triggered ability. The updated wording appears above.

If another effect modifies how much damage your hot source would deal, including preventing some of it, the player being dealt damage or the controller of the permanent being dealt damage chooses an order in which to apply those effects. If all of the damage is prevented, Don’t Try This at Home’s effect no longer applies.

The hot thing doesn’t need to be the focus of the illustration, nor does it need to be the actual card being depicted. It just needs to be somewhere in the art. It could even be a sticker.