Reviews > Clothing > Underwear > Hot Chillys GeoThermal Tops and Bottoms > Roger Caffin > Long Term Report

Long Term Report - Hot Chillys Geo Thermals
Roger Caffin
7-April-2005, revised May-2006

Biographical Details

Reviewer:	Roger Caffin
Age:	59
Gender:	M
Weight:	61 kg (134 lb)
Height:	166 cm (65")
Email address:	r dot [surname] at acm dot org
Home:	Sydney, Australia

Backpacking Background

I started bushwalking (the Australian term) at 14, then took up rock climbing at University with the girl who became my wife and is my walking partner. Later on we took up ski touring and canyoning. Winter and summer, we prefer long hard trips by ourselves: about a week in Australia, up to two months in Europe/UK. We prefer fast and light in unfrequented trackless country. We would be out for at least three months a year. Over the last four years we have reduced our pack weights from 18 - 20 kg (40 - 45 lb) each to about 12 kg (26 lb), including food, for week-long trips. I designed and made much of our lightweight gear myself.

I am also the maintainer of the Australian aus.bushwalking FAQ web site www.bushwalking.org.au/FAQ/.

Product Information

Preamble

This Test was a lesson for me in properly reading the product description. I started out expecting winter-grade thermal underwear, but the Hot Chillys web site did say that the garments have a 'Relaxed fit' and a 'Lived-in feel for active or casual use'. I had to reset my expectations. Ordering clothing over the web is not as simple as some would have us believe: I need that 'touchy-feely' bit.

However, during the period of the Long Term Report I discovered a significant health problem for my skin which, at the time, seemed to be directly linked to my wearing of this clothing. This is discussed below. However, later testing in 2006 did not show this problem.

Long Term Testing

Testing has been done in two parts: at home and on trips. After my initial misunderstandings were sorted out I focused on wearing the clothing at home. Overall it proved quite comfortable, but not without a few issues.

Bio-Silver®

The Bio-Silver effect still seems to be present, even after the 6 months of testing and washing. Without a laboratory test I could not say how effective it still is, but it is still working.

Tops: Zip neck vs Crew neck

I have found the Crew Neck design quite comfortable all along, while the Zip neck had to be worn over something else to avoid rapid irritation from the zipper on my chest. That said, both have been very comfortable in a casual style when worn over other clothing.

Trousers

The trousers were more of a problem, especially with the prominent fly at the front. In fact, there were few occasions when they were of any use - but it must be remembered that my Test period has been mainly over the Australian summer. Had it been over the winter period I might well have worn the trousers under single-layer nylon track pants. The combination would be similar in construction to a pair of lined track pants such as I often wear then.

Subsequent testing during the following winter, after the end of the Long Term Report period, comfirmed that they are quite nice under single-layer nylon track pants.

Warmth

My Field Report went into how much of a temperature difference the tops and trousers made for me. Basically, I found that they gave just a couple of degrees of difference. But this is quite consistent with the claims on the web site. I did try them out on a few trips in the summer (as shown above), but I found I could not justify the extra weight.

Fit

I have not noticed any significant amount of stretch in the fabric. While I cannot say whether this is really due to the fabric construction or simply reflects the fact that the clothing was a loose fit, I note that the elbows haven't changed in shape. I think the fabric should get the credit.

Wear and comfort

The inside surface of the tops has retained the fleecy nature and the comfort over the Test period. However, the outside surface has been slightly less satisfactory. The tops show an amount of pilling on the knobbles of the fabric over most of the front, some of the back, and areas on the sleeves. I don't think I rubbed up against anything in particular to cause this; it seems to have happened over time in ordinary everyday use. But it is visible, especially when viewed at an angle, and has not happened in this manner on any other clothing.

As mentioned above I eventually restricted use of the clothing to around the home, but even so I managed to get a couple of bad snags in the fabric. I have mistreated ordinary cotton knit tops far worse than this without this problem. I tried to 'pull' the fabric out to get the loops to retract, but this was completely unsuccessful.

Uncertain Health Issue (revised 2006)

I mentioned in previous reports that the zip at the neck had caused me some skin irritation - a bit of a red rash. This reaction was more severe at the time than I had expected. Since then I have mainly worn the zip-neck top over other clothing, both for this reason and because the top was not that warm in itself. Worn thus it is fine.

However, on a couple of occasions when I wore the tops over a short-sleeve T-shirt I had problems. I developed itchy red areas on my skin, especially the more sensitive inside surfaces of my arms, and these became mild rashes during the day. This happened even just after the tops had been washed. At first I did not connect the rashes with the fabric, but over the period of this Long Term Report the correlation seemed to be quite strong. On the last wearing I found I was getting a definite rash on my forearms and a couple of small blisters started to form. This seemed to me to be typical of an allergic reaction to nickel (one of my children is allergic to nickel), but as far as I know there should not be any nickel in the Hot Chillys fabric: just silver ions. It might have been useful to have photographs of the reaction, but I didn't take any at the time. This has caused me to abandon wearing these thermals during the period of the Long Term Report.

Health Addendum - 2006

I was left puzzled by the rash on my skin and was not willing to wear the clothing any more for half a year. However, sometime since the end of the Long Term Report period (April-2005) I started wearing the tops again, and the rash on my arms never reappeared. The raw zip at my neck does continue to irritate my skin, and the manufacturer really should fix this, but that's all. I have to conclude that there must have been something else happening at the same time, something not associated with the Hot Chillys fabric. Accordingly I withdraw any suggestions that the Hot Chillys fabric caused me any problems, and indeed the thermals have been quite comfortable when worn at home.

Assessment

These are mainly the points I listed in my Initial Report for assessment.

• Warmth
  Very limited, but consistent with the advertised casual use.
• Warmth per weight
  Not suitable as 'thermals' for the ultralight walker.
• Comfort
  Apart from the zip, very casual and comfortable.
• Fit
  As advertised, and a 'relaxed fit'. Easy to get on and off.
• Smell
  To my surprise the Bio-Silver treatment did seem to work.
• Washing
  They have washed well, with no sign of damage.
• Cuffs
  Both the simple cuffs and the band cuffs have survived very well.
• Wear
  This result was not so good. There was a lot of pilling and the fabric snagged rather easily.
• Waist region
  The waist band on the trousers worked fine. The tops were quite long enough.
• Neck
  The crew neck is just fine for comfort.

I could not enjoy the zip top by itself as the zip seriously irritated my skin.

Summary

• In my opinion, these are meant for casual use, not as 'thermals' in the conventional outdoor clothing sense.
• I would consider buying the Crew Neck top as a conventional skivvy for home use in fine weather (subject to a price check of course).
• The Zip top would also be nice as casual wear in fine weather if worn over something else, but definitely not by itself unless the zip arrangement was improved.
• The trousers are well made and I have worn them in winter at home under other light trousers, but in practice I would not be likely to buy them for Australian conditions.

Reviews > Clothing > Underwear > Hot Chillys GeoThermal Tops and Bottoms > Roger Caffin > Long Term Report