From PsychoSquad: “While engaged in combat in Cyberpunk 2077, you might sometimes notice being set on fire and dealt constant incendiary damage for a couple of seconds. This is due to a combat mechanic called Overheating. It is not uncommon for some implants to get overheated in a world full of high-grade tech and cybernetics.”
Source: N4G PC What Is Overheating And How To Avoid It In Cyberpunk 2077