A genuinely distinct Vegas format
Vegas pool parties, often branded as day clubs, run full nightclub-style production — DJs, dancers, bottle service — during daylight hours at a resort pool, and are a specifically Vegas invention driven by the city's near-constant sunshine.
Tickets and cabanas
General admission gets you into the pool deck and the party; cabana or daybed rentals get a dedicated shaded space for a group, at a significant premium — worth it for a group celebrating something specific, overkill for a casual afternoon.
Sun and hydration
It's still desert sun for hours at a stretch — sunscreen, hydration and pacing yourself through both the heat and the day-drinking are worth taking seriously, even in the middle of a party.
Seasonal
Day clubs generally run seasonally, roughly spring through early fall — check a specific venue's calendar before you build a trip around it outside peak pool season.