The Science Behind Evaporative Cooling Gear

It can be challenging to stay cool when you spend long hours fishing, hunting, working, or exercising, especially during hot summer months. One effective way to help lower your body temperature is to use evaporative cooling gear, which works differently from putting a cold pack on your head or wrapping a regular wet towel around your neck.

In this article, the outdoor gear experts at Frogg Toggs explain the science behind how evaporative cooling products work without harsh chemicals to keep you cool, how easy they are to activate, how long you can expect the cooling effect to last, proper washing and storage tips, and answer other frequently asked questions.

How Evaporative Cooling Materials Work

Evaporative cooling materials, such as PVA and microfiber, work by absorbing and retaining water, which then gradually evaporates from the material's surface. As the water evaporates, it pulls heat away from the wet material and the surface of your skin, creating a cooling effect. 

This is the same process your body uses to regulate temperature when you sweat. When your body becomes too warm, it releases moisture onto the skin. As that moisture evaporates, it carries heat away and helps lower your body temperature. Cooling towels and wraps support this natural process by holding water against a larger surface area and allowing it to evaporate over time.

To maintain the cooling effect, the material must stay wet and exposed to airflow. Air movement aids evaporation, and rewetting restores the cooling effect when the material dries. Some cooling products also offer UV protection. To learn more, read “Sun Protection 101: How Cooling Towels and Hats Protect You.”

PVA vs. Microfiber Cooling Towels

PVA and microfiber cooling towels use the same evaporative process but differ in water absorption, texture when dry, and care and storage requirements.

PVA (polyvinyl alcohol) is a synthetic, sponge-like material that absorbs and retains a substantial amount of water. For example, the iCOOL® PVA Cooling Towel can hold up to eight times its weight in water and sweat. PVA remains soft and flexible when wet but hardens stiff when dry. It can be stored damp in a tube or sealed bag, or allowed to dry completely between uses.

A quality brushed microfiber cooling towel, like the Chilly Pad® PRO, absorbs water through fine, fabric-like fibers and has a lighter, softer feel. It stays flexible whether wet or dry, making it easy to fold, pack, and store without special handling.

Cooling Without Harsh Chemicals and Safe For All Ages

Frogg Toggs cooling towels do not use harsh chemicals. They rely solely on water and evaporation for cooling. Once wet, the material absorbs water, which then evaporates and draws heat away from the material and your skin.

Frogg Toggs non-toxic cooling towels are safe for all ages when used as directed, but young children should be supervised, especially if wearing a towel around the neck, to ensure it remains loose and does not restrict breathing or movement.

It is also important to remember that while cooling towels provide relief in hot conditions, they should always be used alongside proper hydration, shade, and breaks from the heat.

How to Activate a Cooling Towel: Wet, Wring, and Snap

Activating a cooling towel takes only a few seconds and requires nothing more than clean water.

• Wet or soak the towel: Fully saturate the material with clean water so it absorbs enough moisture for effective evaporation.

• Wring out excess water: Gently wring or squeeze the towel until it is wet but not dripping.

• Snap the towel: Some instructions suggest snapping the towel in the air once or twice before use, though this is not required for all materials.

After activation, place the towel around your neck, across your forehead, or against another area of exposed skin. Don’t put it under your clothes. Keeping the material exposed to airflow supports evaporation and maintains the cooling effect.

When the towel dries or loses its cooling effect, simply rewet it, remove excess water, and repeat the process. No refrigeration, batteries, or additional products are needed.

Duration of Cooling: How Long Does a Cooling Towel Stay Cold?

A hyper-evaporative cooling towel typically stays cold for 1 to 5 hours per activation. The exact duration depends on fabric construction, how it is used, and environmental conditions. Air temperature, humidity, sun exposure, airflow, activity level, towel saturation, and the amount of water removed before use all affect how long the cooling effect lasts.

Cooling towels are most effective in hot, dry, or breezy conditions, where evaporation occurs more easily. High humidity slows evaporation and shortens the cooling period before reactivation is needed.

The towel’s material also affects cooling duration. PVA towels are thick and rubbery, holding more water and staying cool longer before needing reactivation. Microfiber cooling towels are lighter, hold less water, and may require more frequent rewetting.

Regardless of duration, the great thing about evaporative cooling gear is that it can be reactivated as often as needed throughout the day.

Care Instructions for Cooling Towels and Wraps

Cooling towels and wraps are easy to care for, but the exact washing, drying, and storage instructions can vary by material. Always follow the care directions provided with your product.

Microfiber

Microfiber cooling towels can be hand-washed or machine-washed on a cold, gentle cycle with mild detergent. Air drying is recommended to protect the fibers, as high heat can damage synthetic fibers and ruin the towel’s evaporation system.

Because microfiber remains soft and flexible when dry, there aren’t any special storage instructions. Just make sure it is completely dry if stored in an airtight bag to prevent bacterial growth.

PVA 

Hand wash or machine wash PVA cooling towels on a gentle cycle with standard detergent. Hang dry only. Do not use a dryer, as direct heat can make the polymer brittle and cause cracking or tearing.

Because PVA naturally dries hard, it requires special handling when storing. For short-term storage, roll the damp towel and place it in its original tube or a sealed bag. For long-term storage, roll it loosely or lay it flat before it hardens. Never fold, bend, or force a dry, stiff PVA towel, as it could crack, tear, and permanently ruin the material. Pack it away in a dry place with the tube lid slightly open to allow moisture to escape.

Care Guidelines for All Cooling Towels

Do not use harsh cleaning products, fabric softener, or bleach to clean cooling products. The only exception would be if a PVA towel has mold or mildew. In that case, you may be able to use a highly diluted mixture of no more than 1 tablespoon of bleach per gallon of water. You also never want to use an iron on evaporation cooling material. The intense heat will instantly singe the cooling filaments.

Other Evaporative Cooling Gear FAQs

What is the difference between a cooling towel and a regular wet towel?

A regular wet towel can only provide temporary relief for a few minutes. Cooling towels use absorbent materials that hold and distribute moisture for longer-lasting evaporation. They are also lighter and easier to wear on the neck, head, or other areas where you want cooling relief.

Can you put a cooling towel in the refrigerator or freezer?

Some PVA cooling towels can be refrigerated after washing and sealing in a bag, but should not be frozen. Freezing can make the towel brittle and cause damage. Always check the care instructions for your specific cooling towel before refrigerating it.

Do cooling towels really lower body temperature?

Yes! Cooling towels help lower body temperature by drawing heat away from the wet material and your skin as water evaporates. However, a cooling towel should be used alongside proper hydration, shade, and breaks from the heat, and it is not a substitute for medical care if someone shows signs of heat exhaustion or heat stroke.

Can you wear a cooling towel under clothing or while sleeping?

PVA cooling towels should not be worn under clothing or while sleeping. Evaporative cooling requires airflow, and covering the material prevents water from evaporating efficiently. For the best results, wear the towel against exposed skin and keep it open to the air.

How do you reactivate a cooling towel once it stops cooling?

When a cooling towel dries or loses its cooling effect, all you have to do is rewet it with clean water and wring out the excess. This restores the moisture needed for evaporation and reactivates the cooling effect. You can repeat this process as often as needed throughout the day.

Find the Best Evaporative Cooling Gear at Frogg Toggs

Frogg Toggs evaporative cooling gear is a great summer addition to your essential fishing gear, to have on hand for hunting trips and hikes, golfing, and for exercise and working jobs in the heat. Cooling towels are also popular for women experiencing hot flashes and are often used by athletes of all ages.

Hyper-evaporative cooling gear is available in various materials and styles. Frogg Toggs offers a full range of cooling products, including towels, headwear, bandanas, wraps, headbands, hoodies, and neck gaiters.

If you aren’t sure where to start, two best-sellers from Frogg Toggs are the soft, lightweight Chilly Pad® PRO Microfiber Cooling Towel and the highly absorbent iCOOL® PVA Cooling Towel 2-Pack.

Explore all Frogg Toggs cooling products to find the option that best fits how you need to beat the heat.