Marathon uses Heat as its stamina system. Your Runner builds Heat when you sprint or use movement-heavy abilities, and once that meter fills, your mobility sharply drops until it cools back down.
What Heat is in Marathon
Heat is the built-in limit on how long your Runner can keep moving at full intensity. It is not a health stat, and it is not a shield. It functions as a movement budget that controls sprinting and certain traversal abilities tied to your shell.
The practical result is simple. The more aggressively you move, the more Heat you generate. If you treat every fight or escape like a constant sprint, you will eventually hit a hard stop.
What causes Heat to build
Heat rises from movement-based actions. Sprinting is the main trigger, but it also increases when you use mobility tools attached to specific Runner kits, such as a dash or double-jump.
That makes Heat a system-level rule, not just a sprint bar. It governs how often you can chain movement options before your shell needs to recover.
What happens when you overheat
Once the Heat meter fills, your Runner becomes much less mobile. Sprinting is disabled, and any other movement actions that add Heat are effectively locked out until the cooldown finishes.
This is the part that matters in actual matches. Overheating does not just slow you down a little. It removes your ability to reposition on demand, which can leave you exposed in the open or unable to finish an escape.
How the Heat system changes movement decisions
Heat forces a tradeoff between speed and control. You can burn it early to cross open ground, rush loot, or break line of sight, but doing that reduces your options a few seconds later.
That makes Heat less about raw endurance and more about timing. Good movement in Marathon is not constant movement. It is knowing when to spend the meter and when to let it recover so you still have mobility when a fight turns.
How Heat cools down
Heat drops when you stop feeding the meter with sprinting or other movement abilities. The cooldown becomes especially useful when you slow your pace and avoid actions that keep pushing the bar upward.
Crouch walking is one of the safest ways to stay mobile while recovering. It lets you keep moving, lowers your profile, and gives your shell time to cool off without committing to a full stop.
Weather and terrain effects on Heat
Heat recovery is not identical in every part of a run. Rain and bodies of water help your Runner cool faster, and moving through those areas also reduces Heat generation compared with normal terrain.
That means the environment can directly affect how long you can stay mobile. If you are planning a retreat or trying to cross a dangerous area, wet routes are easier on your Heat meter than dry ones.
Why Heat matters more than a normal stamina bar
A typical stamina bar often refills quickly and exists only to slow repeated sprinting. Heat is harsher because it punishes overuse with a temporary loss of movement options.
In practice, the system creates a higher penalty for panic movement. If you empty the meter at the wrong time, the problem is not just reduced pace. It is losing access to the exact tools you need when pressure ramps up.
What Heat does not affect
Heat is specifically tied to movement. It limits sprinting and Heat-generating mobility actions rather than acting as an all-purpose resource for every system on your Runner.
For that reason, the cleanest way to think about it is as a shell stress meter. When it climbs too high, your movement package shuts down until the shell stabilizes.
How to tell the system is working against you
You know Heat is becoming the problem when your movement choices start narrowing. First, you feel the need to stop sprinting to let the bar settle. Then, if you keep pushing, sprint and related movement actions become unavailable.
That is the clearest confirmation point. If your shell can no longer sprint after the meter fills, you have overheated and entered the full cooldown state.
Heat in one sentence
Heat is Marathon’s stamina-style movement cap, generated by sprinting and mobility abilities, and overheating temporarily removes those options until the meter fully cools.