Do we need to heat the payload internally ?

When increasing altitude the temperature varies to incredibly low values. The troposphere ranges between 15°C to -60°C , in this layer of the atmosphere the temperature decreases.  As the pressure decreases so does the temperature because they are directly proportional therefore the rate of pressure decrease is the same as the temperature decrease. This is because there are less particles at lower pressures which is higher up in the atmosphere therefore there is fewer successful collisions between particles meaning less thermal energy is created. When we reach the stratosphere (aiming for 30,000m) the temperature starts increasing again from -60°C to around 5°C. The reason for the temperature increasing is because the ozone layer absorbs the ultraviolet light from solar radiation. The electrical components we will be using will struggle to work in temperatures such as these, however the balloon will only experience these temperatures for the duration of under 2 hours. Therefore we are including internal insulation which will maintain the temperature inside of the payload and it will not experience temperatures anywhere near -60°C . Also the payload will absorb some heat from the sun as well. Therefore we will most likely not need an internal heater because of the heat from the sun and the insulation will allow the technology to function.

references:

https://sciencing.com/earths-atmosphere-composition-temperature-19463.html