Minimum R-Value Sleeping Pad

[Heavy Duty]

I use a Mondo King Thermarest sleeping pad with an R value of 11.4.

I do have another pad with a value of 5. I wonder how low of an insulation value you can go while sleeping on snow and not feel the cold. What are your thoughts?

[Lonelake]

I have used a Thermarest Pro Lite and a Zrest, both of which have an R-Value of about 2.5, I was not cold, but my Exped SynMat 7, and DownMat 9 are significantly warmer. I think, for me, that the 2 Thermarest pads would be the least amount of pad insulation I would want to camp with.

LL

[kiggy]

I used Thermarest base camp R6 and rigerest solite R2. if using only one pad, was always cold. so upgraded to Mondo King. sleeping like a baby now, and less bulky then two pads
also bring sometime lamb rag for luxury

[Heavy Duty]

I used Thermarest base camp R6 and rigerest solite R2. if using only one pad, was always cold. so upgraded to Mondo King. sleeping like a baby now, and less bulky then two pads
also bring sometime lamb rag for luxury

Mondo king plus a lamb rag....that's almost better than home! (least for me) 😀

[Moondog55]

Rule of thumb would be [ I guess] equal to the sleeping bags insulation rating.
If using 4Clo per inch and 1Clo is equal to R1.13 then anything less than R10 is too little at -18C
So the MondoKing or equal is on the money.

[Bothwell Voyageur]

Rule of thumb would be [ I guess] equal to the sleeping bags insulation rating.
If using 4Clo per inch and 1Clo is equal to R1.13 then anything less than R10 is too little at -18C
So the MondoKing or equal is on the money.

Except that heat loss through the ground is unlikely to be the same as to the air. On deep snow it should be less due to the insulative value of snow, frozen ground or ice it will likely be higher. I find an xtherm and and a foam pad is good. Probably R8.

[Mewolf1]

When I started in the 70's a 1/2" ensolite pad was all I ever use in combo with an old down army bag. Never got cold. Now it's more a matter of being able to sit up in the morning, so a thicker pad comes with for comfort.

[Moondog55]

My personal experience is that heat loss to the snow and ice is greater than to the air.
Either way if you feel cold underneath then it's simply not enough insulation.
My current system is a RidgeRest Solar XL plus a Sea to Summit Comfort Plus XL so R2.5 plus R4.7 and often it's not quite enough.

[kiggy]

my 99 cents - not adequate insulation of sleeping bag can make you cold and may be give you a cold - I am not talking about extremes as hyperthermia
not adequate insulation from the ground will damage kidney, reproduction system and other vital organs without you noticing it

[Undersky]

A Mondo King is luxurious, I agree. Sleep is long and deep on top of that "mono-mattress"!!
That said, I have enjoyed many full night's sleeps with systems equaling about 2/3 of the Mondo's R-value.
Of course, there are many, many variables in this equation.
Always best to have a little more and deal with the extra weight and packed volume than to have a little too little.
Lastly, it is still worth keeping in mind that carrying two mats gives you a little more redundancy in that one may fail, but it is less likely that both will fail on the same trip.