Renal hypothermia may preserve renal function in patients who require partial nephrectomy. In preparation for a definitive randomized controlled trial this pilot study will assess feasibility and variance data to be used for sample size estimation

Inclusion Criteria:

1. Patients presenting with a renal mass deemed amenable to an open partial nephrectomy regardless of stage or histology.
2. Bilateral renal function on radiographic imaging.
3. Willing to consent to randomization.
4. Willing to comply with study protocol.

Exclusion Criteria:

1. Anatomically or functionally solitary kidney
2. Multiple renal tumours
3. Bilateral renal tumours
4. Life expectancy < 3 months as deemed by treating physician
5. Age less than 18 years old
6. Pregnancy