Help action

With the new rules, do I have to be proficient in a skill or tool to be able to help in that particular context?

Yes, you need to be proficient in the check you're assisting with: https://www.dndbeyond.com/sources/dnd/free-rules/rules-glossary#HelpAction

Assist an Ability Check. Choose one of your skill or tool proficiencies and one ally who is near enough for you to assist verbally or physically when they make an ability check. That ally has Advantage on the next ability check they make with the chosen skill or tool. This benefit expires if the ally doesn’t use it before the start of your next turn. The DM has final say on whether your assistance is possible.

My question is how this effects first aid. Do we need to be proficient in Medicine skill in order to stabilize a character?

Quote from Noble1031 >>

My question is how this effects first aid. Do we need to proficient in Medicine skill in order to stabilize a character?

 

No, you don't. The rules for using the Help action in this way do not mention proficiency, only the rules for using it to assist someone else's ability check.

(Note that in the 2014 rules, making a Medicine check to stabilize someone isn't even a Help action at all, it's just an unnamed action.)

So I'm getting mixed things here. Some sections have the "administer first aid" above the help action in the rules such as in dndbeyond when you look it up. Others like the link above do not have that stipulation. 

So just to confirm and settle this debate, can anyone chime in to confirm. Is using "Help" as an action, basically the same as "Spare the dying", except anyone can use it and they have to be within touch range?

Quote from foozlesnorf >>

So I'm getting mixed things here. Some sections have the "administer first aid" above the help action in the rules such as in dndbeyond when you look it up. Others like the link above do not have that stipulation. 

So just to confirm and settle this debate, can anyone chime in to confirm. Is using "Help" as an action, basically the same as "Spare the dying", except anyone can use it and they have to be within touch range?

Stabilizing a dying character in that way is similar to Spare the Dying, but you do have to succeed on a DC 10 Wisdom (Medicine) check for it to work, which isn't the case with the spell.

In the 5.5e rules, when you do this you're taking the Help action. (Confusingly, this is not described in the Rules Glossary definition of the Help action, but it's in the section on Damage and Healing). The Help action also has a couple of other unrelated uses.

In the 5e rules, stabilizing a character like this works the same way, but it's not the Help action (or any specific named action).