O'Neill Heat Wetsuit Review

O’Neill Heat

Neoprene and Liners

The Heat is entirely made of O’Neill’s top TechnoButter 3 Neoprene (TB3). This is the same stuff you’ll find on their Hyperfreak, and it’s just about the most flexible rubber on the market. Aside from its stretch properties, TB3 is also very lightweight and wears comfortably on your skin. If you have ever owned a Heat in the past, putting this version on will be night-and-day different in terms of weight and flexibility.

Another feature taken from O’Neill’s top shelf is an internal liner that they call TechnoButter Firewall. If you flip the Heat inside-out, this is the red material that runs through ¾ of the suit from the chest down. This is the same internal liner found on some of O’Neill’s most expensive suits, like the Psycho Tech. Basically, this liner is incredibly comfortable, better retains heat in the core and legs of your body, and dries quickly once out of the water.

The arms and shoulders don’t have this liner in them, but that’s only to keep them free and as unrestricted as possible.

Seams and Stitching

As far as seams go, the Heat has the best of the best. The exterior fluid seam weld does an excellent job of sealing seams from cold ocean water. In addition, O’Neill uses durable, chemical-free glue to bind the neoprene panels together.

Fit and Cut

We found this suit to be very comfortable. With a smooth back zip entry, it was easy to get in and out of, and once on, it fit well. These suits run true to size; if anything, they allow for a few extra pounds if you’re just outside the recommended weight. Like all O’Neill suits, the Heat fits surfers with wide shoulders or a big chest especially well.

Entry and Zipper

The O’Neill Heat definitely has a strong following, partially because of its accessible entry system. Nowadays, it’s challenging to find a high-performance wetsuit offered in a back zip option. So, for surfers who love back-zip wetsuits, the vast majority of their choices are entry to mid-level suits.

The back zip entry on this wetsuit is super smooth, using the best zipper in the industry, the O’Neill Red Zone Zipper. The Red Zone Zipper is aptly coated in red urethane and is the most watertight and durable zipper we know of. These zippers thread smoothly and feel like they came off a piece of commercial fishing gear, as opposed to the cheap, thin-style zippers found on other suits.

Performance

When it comes to cold water wetsuit performance, the O’Neill Heat 3/2 and 4/3 more than hold their own. Made entirely from TechnoButter 3 neoprene, this suit feels ultra-lightweight and incredibly stretchy, reducing paddling fatigue and allowing for long, unrestricted surf sessions—even in chilly conditions.

The TechnoButter Firewall lining, strategically placed through the chest, back, and legs, retains body heat without compromising comfort. This thermal layer helps trap warmth where you need it most and dries quickly between sessions—ideal for surfers who hit the water multiple times a week.

For added insulation and wind protection, the smooth skin panels on the front and back work to block cold wind and absorb sunlight—two key factors for staying warm during windy, overcast days in the lineup.

Overall, if you're looking for a high-performance wetsuit for cold water surfing with excellent flexibility, warmth, and comfort, the O’Neill Heat is a standout choice in the back zip category.

Value and Durability

Along with the O’Neill Mutant, the Heat is one of those suits that we never seem to have problems with and rarely see come back to the shop for warranty repairs. It helps that it’s a simple design, which doesn’t really leave a lot to go wrong, especially when it features top-quality materials.

Customer Feedback

“I've been wearing O'Neill Heat suits for over 20 years and would not consider any other suit. They fit great and last if you take care of them. The new Technobutter material allows for greater movement for paddling.”

- Ed

“I’m 6’6,” and 205 lbs, and finding a good wetsuit is way easier than finding a perfect wife/husband/partner. The O’Neill Heat XLT is great. The size fits as perfectly as it could for someone as “circus freakish” as I am, and the comfort of the inner lining is fantastic. So far, the water temps are cool but not cold, so the review is based on comfort and fit alone. 10 out of 10!”

- Tall Guy Review

“This is my second O'Neill wetsuit. The first was exactly what I needed for SoCal winter. The Techno Butter is especially stretchy without giving up warmth. I know this one will be just as good as we head into late fall and winter conditions.”

- Daphne

How the Heat Compares to Other O’Neill Wetsuits

O’Neill Hyperfreak Fire vs. Heat

Hyperfreak Fire is even stretchier but lacks the traditional back zip that many surfers still prefer. The Heat is better for those who want structure and warmth.

O’Neill Psycho Tech vs. Heat

The Psycho Tech is warmer with more insulation, but it's also heavier and more expensive. The Heat offers excellent value without sacrificing too much performance.

Budget Option: O’Neill Epic

The Epic is a good entry-level suit, but if you’re surfing regularly in cold water, the Heat’s premium materials and construction make it a better long-term investment.

Final Thoughts

The Heat back zip wetsuit is an unbeatable value for serious surfers. Out of all the high-end options, it's our top pick due to its more affordable price tag compared with other suits at $100+. Plus, you get uncompromising performance and quality that truly stands out.

Interested in one of thee most high-performance back zips on the market? Take a look at the newly updated Psycho Tech. If you are a fan of O’Neill suits, but the Heat is outside of your budget, we recommend the tried and true Epic line.

Hopefully, this review helped answer some questions you may have had about the Heat. If there's anything we didn't cover or if you have any other wetsuit questions in general, feel free to leave a comment below, send an email to support@cleanlinesurf.com, or call us toll-free at 1-888-546-6176.