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.

You don’t need cold water to get cold. Even in tropical Indian dive sites, your body loses heat every minute underwater. That “slight chill” affects your breathing, nitrogen absorption, and overall safety. Thermal protection isn’t about comfort, it’s a critical part of safe diving. Here’s why every diver should take it seriously.