Just past restaurant row in San Juan Cosala at the base of the Racquet Club area residents can enjoy a spa day at the Grand Cosala Resort, or the boutique hotel next door for under $20 USD. Dip into hot pools that are 110 F, thermal waters, cooler waters, get a facial, a massage - and choose NOT to drive 3.5 hours to the beach --- get-refreshed quick in just 40 minutes from home. The Grand Cosala allows you to enjoy the pools from 10 am - 6:00 pm - even if you check into a room visitors are allowed to change into bathing suits on site, bench it, enjoy a meal at the garden cafe, then check bags into room at 3 PM. The front desk staff speak English and you can book by phone or online.
Attached to Grand Cosala is a Italian Cafe, and in the same shopping center is a garage of Costco goods and a second boutique hotel for a day in the sun with a lovely cafe and view of the lake.
Grand Cosala contact info in comments.
Book facial or massage a few days prior to Spa day.