The Medic is a frail and squishy critter, requiring help from his teammates to survive. Because a non-dead Medic does wonders for your team's ability to keep up pressure, and because an übercharge can turn the tide of a whole game, you should make it a priority to make sure your Medic stays alive. Here are a few different ways to do that.

Bite the bullets
If you're a high-health class with a Medic attached to you, let your him use you as a meat shield. Try to move in a way that makes it easy for him to stay behind you. If you're in a cramped area, you might even want to actively jump in front of critical projectiles headed for the approximate vicinity of your Medic, provided you can survive the blast. For reference, a critical grenade does 270-330 damage, a critical rocket from the Direct Hit does 338 damage, a critical rocket from the Liberty Launcher does 203 damage and a critical rocket from any other rocket launcher does 270 damage. A critical grenade from the Loch-n-Load does 300 damage, which means an overhealed Heavy can survive it, but the weapon's 'shatter on surfaces' trait makes it more worthwhile to dodge the projectile and hope the Medic manages to do the same.

Keep track of your pocket
Medics are the most popular target for ambushes, and you should therefore always be on the lookout for people who want to do nonconsensual things to your Medic from behind. When you're being healed, keep an eye the 'Healer: [name]' overlay and turn around instantly if you see a chunk of the health bar disappear or the Medic stops healing you. Even when nothing suspicious is going on with the overlay, it doesn't hurt to turn around now and then to check for potential spies, and watch the flanks to euthanize stray Scouts.

Don't leave Medics unattended
A lone Medic is easy prey. If you're alone with your Medic, make an effort to protect him from incoming enemies. If your Medic is badly wounded and needs to retreat, retreat with him. If you're playing a suicidal roamer, escort the Medic to some more reliable teammates before you go flying off into the sunset.

Share the health pickups
If you're low on health and close to a health kit, and there's an only slightly hurt Medic nearby, you should leave the kit for him, for two reasons. Firstly, he can heal you but not himself quickly, meaning you'll both get to full health faster if he gets the kit. Secondly, übercharge builds faster when healing players below 142.5%, which means that if the Medic doesn't have any other non-overhealed allies nearby, you picking up the health kit will delay the potential übercharge.

Heal and extinguish them
If you're a Heavy with the Sandvich equipped, you should toss it to wounded Medics whenever the opportunity to do so arises. If you're a Scout or Sniper with Mad Milk or Jarate equipped, use them on burning Medics. If you're a Pyro with any flamethrower that isn't the Phlogistinator, use the airblast to extinguish burning Medics, and also all other burning allies regardless of class. If you're a Pyro with the Phlogistinator, stop being a Pyro with the Phlogistinator because the Phlogistinator is terrible.

If there's one thing more frustrating than playing Medic and being let down by terrible teammates, it's having a Medic and letting him down by being a terrible teammate. Performing badly because you're unskilled, inexperienced or simply having a bad day is of course perfectly understandable, and a Medic who complains about his teammates being poopy at the game is a bad Medic. There are, however, a few things you can keep in mind to better utilize your Medic's help regardless of your personal skill level.

Don't underestimate the power of healing
A lot of people seem to think of Medics as purely ornamental. If you find yourself being healed, you should adapt your playstyle and put yourself at more risk than you otherwise would. Don't just duck in and out of cover with 40% overheal; throw yourself into the heat of battle and go for the objective! That being said...

Don't overestimate the power of healing
On the flipside, even more people seem to think of Medics as instant godmode. Don't put on colorful spandex and stroll into a rain of bullets as soon as a Medigun latches onto your butt. Try to realistically assess the threats you're facing and compare them to your health, your Medic's health and the rate of healing. Don't drag your Medic with you into enemy territory on a rampage destined to end in an untimely demise for both of you. Don't try to take out a sentry by standing in the open and firing at it until you die. Instead, do as much damage as you can against the most important targets, pop back into cover and let the Medic restore you, then pop back out and continue.

Make use of übercharges
If you're a power class and notice a friendly Medic with full or nearly full übercharge, prepare to make use of it. Reload your weapons, position yourself so you can attack quickly and take as much advantage of it as possible. If you see someone else being übered, run in and help them dish out damage. Whatever you do, don't retreat back into your own team's territory if someone übers you. I have no idea why, but a baffling amount of people do that.

Play bulkier classes
It's always a bad choice to have more than two Snipers or Spies, but the appropriate numbers for combat classes is more fluid. It's perfectly possible for a team to do well with 3 Scouts and no Pyros or 4 Soldiers and no Heavies. If your team has a Medic, however, it might be a good idea to lean toward bulkier classes to make better use of his abilites. If you're the second Spy, you might want to switch to Soldier, if you're the fourth Scout you might want to go Demoman, et cetera.

Adapt your loadout
If you're using weapons like the Black Box, Phlogistinator or Candy Cane, consider switching them once your team gains a Medic. As noted in the health kit paragraph earlier, the health bonuses of such weapons become redundant or even counterproductive on a team with a Medic, while their downsides stay the same. Using them, you're essentially nerfing yourself for nothing while telling the Medic you don't trust him to do a proper job. Also, if you're using the Phlogistinator you should seriously stop using the Phlogistinator already.

Hunt in packs
While good pocket pairs can be fairly dangerous, there are few things as devastating as a group of overhealed players fighting together. Try to treat your Medic as a meeting place and encourage your teammates to do the same. Instead of throwing yourself at the objective as soon as you spawn, rally around your Medic and work with your teammates to attack in waves.

A lot of pub Medics are new players wanting to get a feel for the game without having to depend on their own skills to defend themselves; it's like the non-awful alternative to newbies playing as the third Sniper or Spy to stay out of harm's way. Nevertheless, a lot of these Medics make some frustrating common mistakes that are easy to spot. Try to give them constructive criticism in a friendly way before someone else screams abuse at them and makes them want to abandon the class forever.

Tell them to heal multiple players
A lot of Medics pocket one player, and then proceed to do nothing else. Having a default pocket player to keep one safe is a perfectly viable tactic, but ignoring all other allies is not. It's easy to see why they do it; latching onto a player and racking up assists is way easier and can feel more rewarding than running around patching up different players, and pubstomping pocket pairs often make the tactic appear unbeatable to newbies. If you find yourself pocketed by such a Medic, remind them to look after other allies now and then and assure them you'll do fine without them for a couple seconds.

Educate them on the various Mediguns
The purposes of various Mediguns may seem obvious to more experienced players. For a new player, knowing very little about the metagame, being introduced to all four mediguns basically at once and trying to figure them out solely based on the various colored percentages, they can however be a bit overwhelming. I'm not expecting you to type an exhaustive guide to all four in chat, but if you see someone blatantly misusing a medigun, maybe tell them to use the stock Medigun on offense and the Kritzkrieg on defense and postpone using the remaining two until they're more experienced, then encourage them to consult the wiki/community guides page for more in-depth advice.

Encourage them to über different classes
The Medic übering a Heavy is maybe the most iconic scene of TF2. This, combined with the common misconception that the Heavy is the 'strongest' class, tricks many newbies into thinking that übers should only be used on Heavies. If you're confident in your skill playing a non-Heavy class and find a confused, fully charged Medic searching for a Heavy, encourage him via chat or voice commands to use it on you instead. Let him experience firsthand the joys of invulnerable sentry-clearing Demoman, kritzed Widowmaker Engie and Quick-fixed CTF Scout.

Take them under your wing
In the unlikely event that you come across an inexperienced Medic who listens to your advice and takes a genuine interest in improving, why not add him to your friends list and give him comprehensive feedback over multiple matches? If he's poor and hatless, you could even toss him a dirty Pickelhaube some time when he's doing extra well. This kind of guidance will admittedly take a fair bit of effort, but in return you'll get a grateful, moderately decent pet Medic whose matches you can join directly from your friends list.

Finally, the task of playing Medic is often a thankless one. Whether your Medic is a frightened newbie picking up the class for the first time or a disillusioned veteran sacrificing his combat abilities to help all you good-for-nothings perform marginally less terrible, being a decent teammate is the key to making them keep doing it.

Make yourself easy to heal
First, if a Medic wants to heal you, make sure you can be healed. If you're a Spy, don't cloak. If you're a Soldier with the Escape Plan or Equalizer, switch to your primary or secondary weapon. Don't run around in the middle of nowhere and call for a Medic, expecting them to materialize out of thin air. If you want to be healed, you need to actively seek out your Medic. Nobody wants to venture alone into enemy territory because of some tiny speech bubble on the other side of two fences, a cliff and a concrete wall. If a Medic is trying to heal you from a distance with the Crusader's Crossbow, stand still so he can hit you. Similarly, if you're a Scout and a Medic is trying to target you with his medigun, quit jumping around like a hyperactive vibrator for a second or two.

Don't impede them
Übercharge builds at a constant rate during setup, so damaging yourself during that time does not help your Medic build über faster. It does, however, make it more difficult for him to make sure everyone's overhealed once the round starts, so don't do it. And for god's sake, if you see a friendly übersaw Medic sneak up on a distracted enemy, don't swoop in and steal the kill.

Don't expect the Medic to do your bidding
Calling 'Medic' while at low health is a nice and useful thing to do. Calling 'Medic' while at full health because you have an opportunity to accomplish an objective and need the Medic to help you out is also perfectly fine. Repeatedly spamming 'Medic' at full health because the Medic refuses to tag along with you to spawncamp the enemy team until you both die, isn't. A good Medic should try to act in the best interests of his team, including you, but he's not there to do whatever you want him to. If he makes bad tactical decisions, then by all means give him some friendly criticism, but if he seems competent you should leave him to do whatever he judges best.

Be appreciative
While I personally don't notice or care if my heal targets thank me, a lot of Medics do. Pressing z and 2 after being healed is simple enough to do, and there's a good chance it will make your Medic happier, so do it. If someone goes Medic and turns the tide in favor of your team, you could even take the time to type '[Name] is an awesome medic :3' in chat once the match ends. That kind of things cheers people up more than you'd think. This doesn't just apply to Medics, of course; complimenting a Pyro who extinguishes all its teammates, a Spy who saps all enemy buildings right before a rush, et cetera, also makes TF2 a more enjoyable game to play.

• TL;DR versions are for chumps. If you want a TL;DR version, get an attention span and come back. In the meantime, here's a funny picture of Liam Neeson with googly eyes.[i.imgur.com]
  
• This guide is several years old and I have stopped playing Team Fortress 2 since. Most of the contents probably still hold true, but some of the more or specific info (such as weapon stats) may be outdated.
  
• I'm just a half-decent F2P player writing based on my experience of playing in pubs. If there's anything you think I've missed or I've gotten blatantly wrong, please let me know.
  
• My consistent use of 'he' refers to the gender of the classes, not a presumed gender of the players. I'm aware that a significant portion of gamers are women these days, which is nice. On a similar note, I heartily despise homophobia, and if any of the sex jokes came across as homophobic I apologize.
  
• The item displayed in the thumbnail is The Hasslehoffer, created by MultiTrip, Constructor and Jal. Here's the workshop page, if you want to upvote or favorite it or something:
  http://gtm.you1.cn/sharedfiles/filedetails/?id=102729896&searchtext=