What is a major potential problem with DNA evidence? Having too much DNA
Contamination from other sources
Having to heat up DNA to keep it from degrading
Having too many matches to DNA typing

Contamination from other sources.

Explanation:

well first you need the sample of the temperature and gas level. i couldnt write a hypothesis unless i had some data. i think temperature changes will effect volumes of gas because gas changed into a solid or liquid at specific temperatures.