Just read about sleeping pad R-values and had to redo my whole setup
I was browsing a hiker forum last night and saw someone mention that R-values stack when you use two pads. I always thought the foam pad under my air pad was just for insulation, not actually adding to the warmth rating. Turns out my 3.2 R-value air pad plus a 1.5 foam pad gives me about 4.7 total, not the 6.2 I assumed. I tested it on a 35 degree night in the backyard and got cold by morning, so now I'm looking at which combo to swap for colder trips. Has anyone else been confused by how R-values work with multiple pads?