Southsea Sauna is a six-seat beachside sauna on Eastney beach beside the Southsea Beach Cafe, heated by a Harvia electric heater. Guests alternate between the heat and a cold plunge tub, the sea, fresh air or a shower. It is a rustic set-up with no changing rooms, so visitors change on the beach; swimwear is required in the sauna. Sessions are booked online, and the sauna is open 6am to 5pm every day, weather permitting.