I got something tossed into my lap by our sister, not brother, from the Asian country she reminded me of a possible idea.

She uses the warming device for her wrists and neck interchangeably. Looking at the specs:
Product name/title search:
Winter Neck Shoulder Electric Neck Heating Pad Heating Pad for Neck and Shoulders 5 Temperature Modes Adjustable USB Heated Neck
Specification:
Size: 50.5*11.3CM/19.8*4.4 inches
Weight: 80g
Temperature: about 55°C, 50°C, 45°C, 40°C, 35°C
Power supply: 5V2v
Power: 6 watts
USB cable length: 85cm/33.4 inches
Note: This product does not include a power bank
The width of this pad is enough to cover most of the erected penis size out there. Not too big, not too small. The temperature range is dead on from 35C to 55C. This is perfect for temperature diffusion and induction from the device's surface to the penile skin lower surfaces. The low voltage means you can use a power bank for your phone for the unit on-the-go.
Something to think about if you need a warmer and not something as bulky as a massive warming fan, heater, or even a block blower. I'm getting one to test.

She uses the warming device for her wrists and neck interchangeably. Looking at the specs:
Product name/title search:
Winter Neck Shoulder Electric Neck Heating Pad Heating Pad for Neck and Shoulders 5 Temperature Modes Adjustable USB Heated Neck
Specification:
Size: 50.5*11.3CM/19.8*4.4 inches
Weight: 80g
Temperature: about 55°C, 50°C, 45°C, 40°C, 35°C
Power supply: 5V2v
Power: 6 watts
USB cable length: 85cm/33.4 inches
Note: This product does not include a power bank
The width of this pad is enough to cover most of the erected penis size out there. Not too big, not too small. The temperature range is dead on from 35C to 55C. This is perfect for temperature diffusion and induction from the device's surface to the penile skin lower surfaces. The low voltage means you can use a power bank for your phone for the unit on-the-go.
Something to think about if you need a warmer and not something as bulky as a massive warming fan, heater, or even a block blower. I'm getting one to test.