How infrared is different
It warms you, not just the air.
A traditional sauna heats the air, and the air heats you. Carbon infrared panels warm you more directly, so the room feels comfortable at a lower air temperature and most people find they can stay in longer.
The Solara models go indoors on a regular 120v circuit, with a glass door, interior lighting and music over Bluetooth. Outdoor saunas like this one have their own roof, so they can sit right on the patio.