Do you have infrared saunas that can be kept in back yard outside? In Canada
Outdoor saunas are best with traditional electric heaters in them because infrared is not effective in overcoming cool ambient air temperatures.
For example, if it is say 60 degrees outside, the infrared heaters will struggle to get the air in the sauna hot enough to be good for a sauna and assist in your sweat.
Infrared is thermal energy, mostly heating what it bumps into. It really does not directly heat the air.
Traditional sauna heaters directly heat the air, and can easily stay on a little longer to overcome cold (even sub-zero) outdoor temperatures.