Boost your warmth level with the supplementary O'Neill Thermo-X Long Sleeve Crew. Soft, stretchy and odor resistant, the Thermo is a smart accessory for the savvy cold water surfer. Put the Thermo-X Crew on under your existing wetsuit to dabble into colder seasons or to extend an older suits life until a new one is on its way. A cold nipping layering piece that offers an additional shield of core warming protection, the O'Neill Thermo-X Long Sleeve Crew gives incredible insulation with minimal bulk.
Product Info
Cleanline Staff
Michael Says:
"The Thermo-X Long Sleeve is a staple for cold water. In the PNW, we can get some pretty gnarly cold snaps, and I’m not always equipped with the right “bone-dry” wetsuit. These Thermo-X layers turn my 4/3 suit into a great 5/4 alternative. Along with the extra warmth, they also help my suit slide on and off more easily. I definitely recommend any cold water surfer keep one of these thermal layers handy."
Boost your warmth level with the supplementary O'Neill Thermo-X Long Sleeve Crew. Soft, stretchy and odor resistant, the Thermo is a smart accessory for the savvy cold water surfer. Put the Thermo-X Crew on under your existing wetsuit to dabble into colder seasons or to extend an older suits life until a new one is on its way. A cold nipping layering piece that offers an additional shield of core warming protection, the O'Neill Thermo-X Long Sleeve Crew gives incredible insulation with minimal bulk.
Product Features
Maximum core insulation
Water repellency, odor resistance
4-Way stretch fabric/li>
Boardshort connector
Rash protection
50+ UPF
Strategic seamless paddle zones
Super low neck: no interference with wetsuit neck
210g Nylon/Spandex with HyperDry for maximum insulation and minimal water absorption
Warranty
This product is backed by a warranty from the manufacturer. Click below for details on the warranty policy for O'Neill products.
GENERAL WARRANTY INFORMATION AND POLICY
If the product is found to be defective under normal use and proper care,
O'Neill will repair or replace the product at our sole discretion. The
decision to replace or repair a product is made by the O'Neill Warranty
Department after receipt of the defective product. At no time does the
O'Neill offer refunds. Defective product should be returned clean and dry,
postage prepaid. Please include a note with product description, product
defects, requested action, return address (be sure to include postal code,
especially for Canadian addresses), daytime phone number with area code,
customers name and a copy of the purchase receipt sent to the address below.
Suits without a copy of the purchase receipt will NOT BE COVERED UNDER
WARRANTY.
THE FOLLOWING WILL NOT BE COVERED UNDER WARRANTY
Products classified as seconds
Fading from sunlight
Alterations
Materials over 1 year (from date of original purchase), or 90 days for
accessories
Repairs or alterations done by anyone other than O'Neill or an O'Neill
authorized repair facility
Warranty request without original receipt
PRODUCT WARRANTY
Flat-Stitched Products, Glued and Blindstitched Products, and Fluid Seam
Weld Products
Limited 1-year warranty (from date of original purchase) on workmanship
and materials.
Neoprene Dry Suits
Limited 1-year warranty (from date of original purchase) on workman ship
and materials (waterproof zipper excluded)
Accessories
Limited 90-day (from date of original purchase) warranty on workmanship
and materials
GENERAL U.S. AND CANADA REPAIR INFORMATION
For repairs received from the dealer or end user, O'Neill offers:
10 Business Day Turnaround for warranty Stitched Suits
10 Business Day Turnaround for warranty Glued Suits
20 Business Day Turnaround for warranty Fluid Seam Welded Suits
30 Business Day Turnaround for all Non-Warranty Repairs
Repairs are to be returned clean and dry, postage paid. Please include the
name and a daytime phone number with area code, return address, product
description, and requested action.
Send Repairs To:
O'Neill U.S. Warranty Repair
1022 Bay Marina Drive, Suite 140B
National City, CA 91950
Tel: 1-800-331-1637
Returns
If you are not 100% satisfied with your purchase you may return it for a refund, or exchange within 30 days of receiving your order.
Cleanline Surf Wetsuit Return Policy
Holiday Returns
For any orders placed after Nov 1st, 2025, we have extended our normal 30-day return policy to allow returns through January 31st, 2026.
Returns are easy! We understand that in some situations returns may be necessary. We also want you to be stoked on your purchase. If you are not 100% satisfied with your purchase you may return it for a full refund, within 30 days of receiving your order. Items must be in new condition with original tags and packaging.
Please note: We are unable to accept returns on used wetsuits. If you are unsure about your wetsuit fit or have any questions at all, please call us before using your wetsuit and we can offer guidance.
Please refer to our full Return Policy for more details.
O'Neill Men's Rash Guards — Size Chart
The staff at Cleanline Surf specialize in sizing O'Neill Wetsuits and
O'Neill Wetsuit accessories. If you have never tried an O'Neill rash guard
before, we strongly urge you to call us for expert advice on sizing. We do
have a size chart available below, but please take it with a grain of salt.
Sizing Info
This item runs small. We recommend sizing up a full size from what the size chart recommends.
Cold water staple for decades don’t suit up without it good stuff.
M
Mike
Quality Product
Great product love the feel and fit of this and how warm it keeps me will be buying more.
L
Lakesurf
Comfy warm in the cool water
Bought this for cold swimming pools & lakes but so far only used it for helping my kid surf in Lake MI. I have a shorty wetsuit so in the 45 degree water this felt really good. I need a wetsuit but until I break down and buy one, this helps so much compared to just freezing… I kinda enjoy the cold so it’s not too bad.
p
polar bear
warm and soft
I bought this for my husband for winter polar bear dips here in New England. Friendly quick service... fits perfectly from your chart.
C
Cheatin5
Almost as important as the wetsuit itself
I use one of these regularly, along with the shorts. I can usually use a 3/2 when other surfers are in a 4/3. I have comfortably used this and a 4/3 to surf 42 degree water and air temps. Keep it washed or it will develop a funk.
Cleanline Staff Michael Says:
Cleanline Staff
What Our Customers Are Saying