Keep it cool with a Peltier module. These unique electronic components can generate a temperature differential when powered. That is to say, apply 5V to the red (positive) and black (negative) wires and one side will get cold while the other side gets hot. For best results, you'll need to wick away that heat (otherwise the cold side will slowly get warmer). A fan and/or heatsink is ideal.
This module is a 5V module, and is rated for 5W max (5V/1A) but when they plugged them in they seemed to draw more like 1.5A so they suggest Adafruit's 5V/2A power adapter for use.
Peltier Thermo-Electric Cooler Module - 5V 1A (5:20)
- Max current: 1.5A @ 5V
- Suggested Voltage range: 5V to 7V
- Maximum temperature differential (Tmax @ Qc = 0): 65°C
- 127 Peltier elements
- DC Resistance: 2.5 ohms
- Silicone seal
- Dimensions: 30mm / 1.18" x 30mm / 1.18" x 3.29mm / 0.12"
- Wire Length: 289.56mm / 11.4"
- Weight: 11.43g