Heated Seat / Clothing Recommendation

Hi All!

Looking for recommendations for heated seats or clothing, preferably something that is available in Canada.

My wife enjoys heading out on the ice with my son and I usually just to read a book and finds herself cold inside the shelter even with the heater going. Usually on her back and butt while sitting on a typical camp style chair. Would love to find a couple of good options to keep her warm with either a better chair or heated clothing so it is more enjoyable.

For reference, we’re in northern Alberta and a typical day on the ice could be negative 20-40 Celsius.