The body temperature of a whale isaround 38 degrees Celsius, or 100 degrees Fahrenheit.

Thickness of whale blubber is 5cm (~2")thick in dolphins and smaller whales, to more than 30cm(12") insome bigger whales.

Thermal conductivity of whale blubberis (0.15-0.20 W/(m °C) depending on species.

Ocean surface water Average temperatureis about 17 degrees Celsius (62.6 degrees Fahrenheit).

Deep ocean water has a very uniformtemperature, around 0-3 °C

Whales typically swim at ~13.5m/s (14MPH) but can go double that if in danger.

Whale: http://4esoblogjan.blogspot.com/2012/11/seleccion-inteligente.html

Heat transfer coefficients “h” forconvection are typically

Free Convection - Air : 5 - 25(W/m²K)

Free Convection - Water: 20 - 100(W/m²K)

Forced Convection - Air: 10 -200 (W/m²K)

Forced Convection -Water: 50 - 10.000 (W/m²K)

Boiling Water : 3.000 - 100.000(W/m²K)

Condensing Water Vapor: 5.000 -100.000 (W/m²K)

Conduction and convection:

So let’s say there is a whale ~1.00m radius and 8.00m long(model its surface area as a cylinder) with an internal bodytemperature (innards excluding blubber) of 38C swimming in deepocean water of 2.00C at a speed of 13.5m/s the entire day. The whale blubber is 0.100m thick and the forced convection heattransfer coefficient of the water is h=300. W/(m²K).There are 4187 J/Cal. A typical human diet uses ~2000Cal/Day.

How many food Calories (Cal) does the whale need to eateach day just to stay warm?