sauna

A number of fitness clubs ("gyms") have saunas, including facilities at the major hotels.

How often did you plan to go?
 
Go to the YMCA, or fit for less, both have saunas and Im sure they're safe or what ever you meant by that
 
there are several Russian Sauna places in Toronto that you can check out. They are not gay and you can hang out naked - Unfortunately its Men Only or Women Only, not mixed.

Also check out family Korean Sauna - http://ilovesauna.com but you can only be nude in Change room. Saunas are public and you will need to wear shirt and short, which they provide. Tried it a few times but nothing worst than sweating in sauna with cloths on.
 
South Western Bathhouse and Tea Room on Dundas and 427. A Russian banya with food and drinks. Worth a visit, check the schedule.