Sun Soaker is a gear perk that improves your health regeneration during the day. It gives you a steady boost if you mostly play in daylight.
Your health recovers faster during daytime hours. It helps you recover between fights without using a heal.
Wear the Flamingo Cap in the head slot. Gear perks are fixed to the piece of clothing that carries them, so you get this one by wearing that piece, not by unlocking it in a menu.
Only if you play in daylight a lot. A regeneration perk that works all day long is more reliable.