Apr 19, 2026 13:00:00

I tried using a Thermos insulated shoulder bag that can hold three 500ml plastic bottles.

As part of

GIGAZINE's spring giveaway campaign, we were provided with a Thermos ' Insulated Shoulder Bag (RFM-003) ' as a prize, so we took a close look at its appearance and cooling performance.

Insulated Shoulder Bag/RFM-003 | Shoulder Bags & Backpacks | Product Information | Thermos
https://www.thermos.jp/product/series/rfm-00.html

The insulated shoulder bag comes in two colors: beige and black. This time, I received the beige one.

The main pocket opens and closes with a zipper.

The interior is designed to keep things cool, and it can hold three 500ml plastic bottles.

It also has a mesh pocket for inserting ice packs.

There is a buttoned pocket on the front.

There is a zippered pocket on the back.

The back pocket is large enough to hold keys, a coin purse, and other small items.

This is what it looks like when you actually wear it on your shoulder. It has a look that's easy to use for everyday wear.

To test its cooling capacity, I prepared three 500ml plastic bottles that had just been taken out of the refrigerator.

Place one ice pack in the mesh pocket.

Put in three plastic bottles.

The temperature was measured using the infrared camera '

HIKMICRO Mini2Plus V2 '. The surface of the plastic bottle is 8.9 degrees Celsius. The lower temperature area on the left is the part in contact with the ice pack, so the temperature on the right side, opposite the ice pack, was measured.

The zipper of the insulated shoulder bag was closed and left indoors at a room temperature of 21 degrees Celsius. For comparison, an identical ice pack, the same as the one inside the insulated shoulder bag, was placed on a table.

One hour later, the ice pack placed on the desk has softened slightly.

The ice packs inside the insulated shoulder bag were still frozen solid.

The surface temperature of the plastic bottle is 11.5 degrees Celsius.

Two hours after the start of the test, most of the ice packs on the desk had melted.

The ice packs inside the insulated shoulder bag have melted a little, but there's still more frozen space than melted space.

The surface temperature of the plastic bottle is 12.1 degrees Celsius.

And three hours after the test began, the ice pack on the desk had completely melted and was lukewarm.

The ice pack in the insulated shoulder bag still had some frozen parts remaining.

The surface temperature of the plastic bottle was 14.4 degrees Celsius. It remained cool even after 3 hours.

The insulated shoulder bag (RFM-003) is also available on Amazon.co.jp and can be purchased for 2181 yen at the time of writing.

Amazon.co.jp: Thermos Insulated Shoulder Bag 3.5L Beige RFM-003 BE: Drugstore

You can also get it through the following giveaway article. The application period is until 11:59 PM on Sunday, April 19, 2026, so go now!

GIGAZINE's Spring Giveaway Project: 'Answer the survey and take everything!' - GIGAZINE