Not clearly enough to avoid confusion among fans. Clearly. Since there’s constant references to people not understanding or not applying the rules for darkvision.
I’ve seen far more misunderstanding around 5E’s darkvision than infravision. 5E’s been out, what 10 years while AD&D’s been out, what 45-47 years. Still more confusion over darkvision.
AD&D PHB p102. “nfravision is the ability to see into the infrared spectrum. Thus heat radiation becomes visible and differences in temperature allow infrared sight. Warm things are bright, cool things grey, very cold things are black. Most infravision extends to 60' distance. Dungeon-dwelling monsters have infravision to 120'. All infravision is spoiled if a light source is shedding illumination upon the creature possessing the infrared sight capability. Similarly, great heat will spoil the capability.
Thieves hiding in shadows are successful with respect to infravision only if there is a heat/light source nearby to mask their body heat, or a very cold object or radiation to provide similar cover.”
This is further detailed in the DMG, on page 59.
“You see heat. Watch Predator* or clips on YouTube. You’ll get it.”
* Although Predator even gets it wrong because the mud doesn’t warm as it sits on Ahnuld’s pecks.
It’s nowhere near as hard as people make it out to be.