This Exped MegaMat Max 15 sleeping pad is extra wide and incredibly thick, with an impressive R-value of 10.6 it can be used in any weather conditions.
This Exped MegaMat Max 15 Duo Sleeping Pad is one of the thickest and the most comfortable on the market, with an incredible insulation and a great warranty.
FUNDANGO Premium Double Wide Self Inflating Camping Sleeping Pad is very long and 5 cm thick, and with foam insulation that makes it suitable for 4-season camping.
If you are a side sleeper or simply want a very comfortable camping bed, you will want to check this list with very thick sleeping pads for camping.
This QOMOTOP Ultra Thick Self-Inflating Camping Mattress is double-size and comfortable even for side sleepers with its 4 inches (10 cm) foam, and its huge 9.5 R-value makes it suitable for all seasons.