I just bought a Hennessy 4 Season Expedition Zip two-layer hammock with a foam cell pad in-between the two under layers.

I have a trip to Quetico planned for mid July. I'd rather not take the pad as the hammock won't fit in the snake skins plus it's just extra bulk and weight.

I am new to hanging so I'm wondering if experienced hangers worry about being cold underneath at the height of summer.

I was there the same time last year and there was a coupe of nights where the temps got down to about 15C or about 60F.

Wondering where the average threshold temp lies where hangers need insulation?

IMHO you will want some insulation under you. While not familiar with the Hennessy, I found the thermorest neo air packs well and provides both insulation and support adequate for mid summer hangs. I use a homemade inflation bag for the neo air that works great. An underquilt would be even better.

Similar situation. HH 4 season. Going in mid May so temps could be anywhere. Wasnt sure how low the foam pad would go so tried it last weekend. Both days overnite temps 25/26. First nite tried it with diy underquit. Failed, no foot coverage. Second nite added a mylar sheet on top the foam pad, much better. Had extra layers of clothes on besides and a overquilt. Did trip a few years ago in august with just the two layers, no problem. Long road to a short answer. Take a mylar sheet, betting you can get easily in the 50s upper 40s for not much $$ or weight. I think the extra layer of the 4 season helps protect the backside from getting bit by the skeeters too.

rxgac: "Similar situation. HH 4 season. Going in mid May so temps could be anywhere. Wasnt sure how low the foam pad would go so tried it last weekend. Both days overnite temps 25/26. First nite tried it with diy underquit. Failed, no foot coverage. Second nite added a mylar sheet on top the foam pad, much better. Had extra layers of clothes on besides and a overquilt. Did trip a few years ago in august with just the two layers, no problem. Long road to a short answer. Take a mylar sheet, betting you can get easily in the 50s upper 40s for not much $$ or weight. I think the extra layer of the 4 season helps protect the backside from getting bit by the skeeters too."

Yes it comes with the mylar sheet.

So your August trip two years ago you went without the foam pad?

The double layer was as much a consideration for mosquitos as insulation. My canoe trips are almost always during peak mosquito season.

bhouse46: "IMHO you will want some insulation under you. While not familiar with the Hennessy, I found the thermorest neo air packs well and provides both insulation and support adequate for mid summer hangs. I use a homemade inflation bag for the neo air that works great. An underquilt would be even better."

I do have a compact Therm-A-Rest; however, the the pad that comes with the Hennessy is made to fit between the hammock layers and locks into position. It is also less bulky but also less of an R-value. But for a July trip the Them-A-Rest R-value would likely be overkill.

Argo: "

rxgac: "Similar situation. HH 4 season. Going in mid May so temps could be anywhere. Wasnt sure how low the foam pad would go so tried it last weekend. Both days overnite temps 25/26. First nite tried it with diy underquit. Failed, no foot coverage. Second nite added a mylar sheet on top the foam pad, much better. Had extra layers of clothes on besides and a overquilt. Did trip a few years ago in august with just the two layers, no problem. Long road to a short answer. Take a mylar sheet, betting you can get easily in the 50s upper 40s for not much $$ or weight. I think the extra layer of the 4 season helps protect the backside from getting bit by the skeeters too."

Yes it comes with the mylar sheet.


So your August trip two years ago you went without the foam pad?


The double layer was as much a consideration for mosquitos as insulation. My canoe trips are almost always during peak mosquito season.


"

At the time, mine didn't have the mylar sheet, but then I may have found it on flea bay.
And, yes on the august trip just used the double layer and no foam pad. Temps were very warm, prob 80s during the day. Did have a couple thunder boomers roll through and temp drops but don't recall it being a problem.
I will take the foam pad in May.

Good golly yes you want a pad or UQ...

Apologies for my ignorance, is the mylar for heat retention, or anti-skeeter armor?

It reflects heat back to you and I would say it also adds a layer of wind block. However, it doesnt breathe so there could be moisture trapped between you and it

I use a 20 degree under quilt and top quilt all year around. When it's warm, I let the under quilt hang down a bit, and sometimes push my top quilt aside. With nothing under you for insulation your backside will likely get cold even at 60 or 65 degrees.

Try sleeping naked on the basement floor. That's kind of what it's like leaving your backside without insulation :-) Basements stay at about 60 degrees. Try your hammock in the basement.

HayRiverDrifter: "I use a 20 degree under quilt and top quilt all year around. When it's warm, I let the under quilt hang down a bit, and sometimes push my top quilt aside. With nothing under you for insulation your backside will likely get cold even at 60 or 65 degrees.


Try sleeping naked on the basement floor. That's kind of what it's like leaving your backside without insulation :-) Basements stay at about 60 degrees. Try your hammock in the basement."

Thanks. That 60-65 degree threshold sounds like the consensus and easily possible in Quetico in July. Unless I get a forecast before my trip that it's going to be 100% balmy in the evenings, the pad is coming.

Now about trying to get me out of my clothes...geez you could at least offer to buy a fella a couple of drinks first! :)

I'm glad you decided to take it, even 60 will give you cold butt syndrome. People should remember that the HIGHEST average July low is 55 and that the record is 35. I have twice had it dip in to the 30's in July, both times unexpected.

if it is in the budget, I would recommend an underquilt vs a pad. Pads easily move around and don't cover shoulders.

He has the Hennessy so the foam pad is different with the 4 season than a regular sleeping pad. It goes between the two hammock layers. But with the zip he would be more able to use an underquilt vs the classic bottom entry.

rxgac: "He has the Hennessy so the foam pad is different with the 4 season than a regular sleeping pad. It goes between the two hammock layers. But with the zip he would be more able to use an underquilt vs the classic bottom entry."

It is secured with end straps as well so it doesn't move from the sleeping position.

But it looks to be more of an intermediate system and not sufficient for temps below about 40F. It also includes one of those heat-reflecting space blankets you can insert either over or under the foam pad but I'm not sure how much additional warmth it provides.

I did use it recently an a couple 25/26 degree nites. Had 20 degree over quilt, puffy jacket, balaclava and lite weight jogging pants. Feet were cold but thats not unusual for me even at home. Also had the overcover. Prob will add some down booties. I couldnt find anything definitive or suggestive how low that set up would go. Have a backpacker classic so wasnt sure i could even use an underquilt with the bottom entry.

Most nights on my recent Q trip went down to about 16C-17C or about 60F. This would likely have been too chilly without the pad. Even with the pad the temp dropped to 10C-12C (50F - 54F) one night and it was a bit chilly underneath.

I thought I could get by without an underquilt but my backyard testing proved otherwise. Even when I could get to a comfortable temperature the pad just wrecked the hammock experience for me.

I purchased a simply light designs trail winder (40 degrees). I field tested it in my backyard when the temps dropped to 36 in April and slept the whole night comfortably.

When I took it on a trip in late July when the lows never dipped below 58 I was just as comfortable. Can’t recommend it enough.

Hammertime: "I thought I could get by without an underquilt but my backyard testing proved otherwise. Even when I could get to a comfortable temperature the pad just wrecked the hammock experience for me.


I purchased a simply light designs trail winder (40 degrees). I field tested it in my backyard when the temps dropped to 36 in April and slept the whole night comfortably.


When I took it on a trip in late July when the lows never dipped below 58 I was just as comfortable. Can’t recommend it enough."

My hammock has a double layer and the pad is built and secured at both ends (but also removable). In terms of comfort, you don't know it's there. Below about 50 F I found it not sufficient. Other insulating items can be added between the lays such as a space SnugPak Jungle Blanket (which I have but have not yet tried). I camp in spring and fall when temps get towards freezing or sometimes below that. I will likely just bite the bullet and get an under-quilt.