Why do some divers feel cold faster than others in the same water? This chapter breaks down how body type, age, dive profile, and hydration affect heat loss—and how to choose thermal protection that actually works for you.

Thermal protection is more than choosing between a wetsuit and a drysuit. In Chapter 4, we explore Sharkskin, hoods, hooded vests, heated systems, and advanced materials that help divers stay warmer, longer, and smarter underwater.

When a wetsuit is no longer enough, drysuits take over. Learn how drysuits work, why they outperform wetsuits in cold or extended dives, and when you should make the switch for better thermal control, safety, and performance underwater.

You already know you’re getting cold on every dive. Now it’s time to understand why and how to control it. From hidden heat loss through breathing to the real science behind wetsuits and neoprene compression, this guide breaks down what actually keeps you warm underwater and how to choose the right thermal protection for tropical diving.