Scott asks: I love merino wool apparel, but above 70 degrees I find shirts and singlets ineffective (they get saturated with sweat and clingy, and stay that way). Yet my merino wool socks, which are getting less ventilation, don't get like this, despite my high sweat rate. How do you explain this?

At first blush, wool and summer do not seem like a good mix. Yet merino wool is renowned for both wicking moisture and fighting odors—both highly desirable for runners in the warmer temperatures.

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“There are many factors that could cause sweat saturation and a clingy feeling in even a naturally moisture-wicking fabric like merino wool,” Needels said. “The very lightweight garments in the 170g/m2-weight fabric (grams per square meter) really should perform very well in high heat. Though the shirt will feel damp when you take it off, you really shouldn’t notice much moisture while you’re wearing it.

“High-quality merino wool wicks sweat away from your body and transports the moisture away from the skin where it can evaporate. As you approach the 200g/m2-weight mark in wool, the garment will be a bit thicker and could hold more moisture in warmer weather.

“Also if you’re in a very humid climate, this can really affect the evaporation rate. I would suspect that if the wool is getting saturated, cotton would be five times worse in the same conditions.

“As for the socks, they may have some other blended fibers in them that assist in transporting the moisture away from the foot. Some people do prefer the super-lightweight synthetics in high heat as they do dry quicker than natural-fiber garments. One big issue with synthetics when you sweat is the odor, which often remains even after laundering.”

Because it’s a natural fiber, merino wool running apparel typically costs more than synthetic facsimiles—especially the 100 percent variety. Sheep upkeep can’t be cheap. Merino wool baselayer shirts from Woolx, for instance, range in price from $68 to $145. However, their softness and durability can ultimately even the scales. If you’re nervous at taking the plunge, consider a final comment from Needels.

“Keep in mind the Woolx garments are 100 percent guaranteed,” said Needels. “So if you try some of them and they do not perform to your liking, you can return them for a full refund.”

And merino wool is not limited to socks and baselayers. I’ve run recently in a pair of SmartWool shorts with a liner made mostly of merino wool. The liner’s soft feel, moisture management, and odor control have shined in heat and humidity.

Plantar Fasciitis

Ashley asks: I am currently rehabbing a bad case of plantar fasciitis on my left foot. What kind of shoes and recovery equipment do you recommend for my comeback?

BRD Sport makes a brace specifically for runners suffering from plantar fasciitis. It retails for $75 and comes with an adjustable strap to dial in the support.

You can run while wearing the brace, and it's washable by hand. And to boot: BRD Sport designs, develops, and produces all of its braces in the U.S.A. (New Jersey to be precise).

Bear in mind that BRD Sport fits braces by ankle size, not by shoe size. Visit the BRD Sport website for a sizing chart and also a video on how exactly to size.

As for shoes, perhaps consider trying a different style, if not an entirely different brand, unless you’ve ruled out shoes through trial and error as a contributing factor.

And as a tool for massage, try freezing an ordinary golf ball. Roll it under your foot. (Here’s much more information on preventing and treating plantar fasciitis from Runner’s World.)

Hydration Packs

Atlee asks: I am looking for a hydration pack, for marathons or ultras, that has the most storage space in the front so I don't have to remove it to get fuel, cell phone, salt tablets, etc. Which hydration pack has the most up-front storage space?

Health - Injuries We may earn commission from links on this page, but we only recommend products we back: two pockets for your smartphones, four pouches for your fuel, and two smaller pockets for your salt tablets. This does not include the two big holsters up front that accommodate a pair of 20-ounce water bottles.

If you opt for the 70-ounce reservoir (sold separately) as your water source, ditch the two bottles and use those holsters for additional storage. There’s a cord with each holster that tightens to secure whatever you toss in there.

Heads up: We reviewed a number of hydration-on-the-run options— packs and otherwise—in the What You Need to Know About Plantar Fasciitis Runner’s World.

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Each Tuesday, Runner’s World gear editor Bryan Boyle answers questions in the Ask the Gear Guy series. Have a question about gear? CA Notice at Collection.