At 115 watts, even above 50 watts, things heat up due to the current (amps) being pulled/generated. All this current is passed from or through the 3 major components, batteries, coil, and bodies of the mod and atomizer. Batteries the more amps pulled from them, more they heat up and need time to relax to cool back down, this cool down period is done through passive means, air surrounding them and thermal conductivity to anything touching them, battery tray inside the mod, circuitry and terminal contacts, the mod itself. The coil, like batteries, radiates heat and cools off through evaporation, vaporizing juice, when evaporation kicks out, Cooling shifts to passive like batteries through thermal conductivity, from anything the coil is in contact with, coil housing, juice, to tank/atomizer base, down into the mod. During firing, all that electricity flowing, flows through the mod and atomizer housings, this increases it's temperature slightly.
All three of those conductive elements combined at once compound upon each other, but the critical temperature is the batteries, batteries go nuclear at about 100C (212F) to 120C(248F), by the time you get half way to that point, the mod and batteries would be hot enough to burn your hand at about 54.4C (130F), not to mention the tank would be hot enough you wouldn't be able to touch it to your lips. If it is getting to warm to your safety concerns, set the mod aside to rest for about 30 minutes and rotate to a new device/ setup.