PHB p. 185 says you can attempt a DC 15 Heal check to stabilize a dying character, and doing so doesn't change their hit point total.
It also says you can attempt a DC 10 Heal check to allow an adjacent character to use their second wind. Page 295 (Healing the Dying) says that if a character receives a healing effect that requires use of a second wind and has none, they are restored to 1.
So why would you ever attempt a DC 15 to stabilize when you could attempt a DC 10 that, at worst, brings them to 1? I can't find anything stating that a skill does not generate an "effect", nor that the DC 10 application of Heal only applies to conscious characters.
It also says you can attempt a DC 10 Heal check to allow an adjacent character to use their second wind. Page 295 (Healing the Dying) says that if a character receives a healing effect that requires use of a second wind and has none, they are restored to 1.
So why would you ever attempt a DC 15 to stabilize when you could attempt a DC 10 that, at worst, brings them to 1? I can't find anything stating that a skill does not generate an "effect", nor that the DC 10 application of Heal only applies to conscious characters.