Sunburn

Sunburn occurs when Sims stay outside in the sun too long. It was introduced with Seasons and with Bon Voyage, where a Sim can get a sunburn on Twikkii Island. It can also occur from prolonged exposure to the sun from sunbathing on the beach. When a Sim gets a sunburn, their face and portrait turns red.

Sometimes if a Sim is in the sunburned position for too long they will faint and will have suffered heatstroke. This can be resolved in 3 ways:
 * Wait for nightfall, when they will cool down.
 * Another Sim may bring a glass of water to them, and tip it over them. This cools the Sim down.
 * Weather changes also appear to wake Sims with heatstroke

Heatstroke can be avoided by cooling a Sim, either by having them drink lemonade or water from a sink, or moving them indoors or into a pool. Putting them in a hot tub is not recommended though.

After around 3 days, the sunburned Sim will revert to normal. If it doesn't revert, then the player is experiencing a known bug and the Sim in question will remain burnt forever. The only known remedy is to download a third-party hack, the FFS Lot Debugger, and use it to reset a burnt Sim.