The life cycles of high-mass stars (≥ 8Mʘ) have a major impact on the evolution of galaxies, while in turn, the position of a molecular cloud in the Galaxy has a major impact on the efficiency and type of star formation which occurs therein. Assuming that if a giant molecular cloud (GMC) began with the same molecular abundances throughout, then any changes observed between different clumps within that GMC will be due to its stage of star formation. By studying how these stars form, we will be able to identify how they shape their surrounding environment. To do this, I have studied two contrasting GMCs: G333, (l = 333ᵒ, b = -0.4ᵒ; d ~ 3.6 kpc) and Vela C (l ~ 265ᵒ, b ~ 1.5ᵒ; d ~ 700 pc). For G333, I am enhancing a 3-mm Mopra survey by including pointed ammonia observations targeted towards star forming clumps with the 70-m Tidbinbilla radio telescope. For Vela C, I have surveyed the region in a variety of tracers across the Mopra millimetre bands. By targeting star forming clumps and using the lowest inversion transitions of ammonia, the temperature variations throughout the two clouds can be analysed. By combining the molecular information with archival dust maps from the Spitzer and Herschel space telescopes, the impact of star formation can be determined.