This is a feasibility study at a single site, Cincinnati Children's Hospital Medical Center. The hypothesis will be tested using a prospective study design. The purpose of the study is to determine tolerability and safety of remote ischemic conditioning in pediatric and adolescent patients undergoing HSCT, with the goal of a larger trial of efficacy to follow. The secondary purpose is to determine if remote ischemic conditioning will reduce subclinical cardiotoxicity as measured by markers of myocardial injury and stress in patients undergoing HSCT. The study will include multiple blood collections and echocardiograms.

Inclusion Criteria:

1. Pediatric, adolescent, or young adult patients, 10 years of age or above.
2. Able to tolerate upper arm blood pressure inflation.
3. Participating in the BMT Biorepository (2012-1156).

Exclusion Criteria:

1. Systolic blood pressure >160 mmHg.
2. Previous diagnosis of cardiomyopathy (dilated, hypertrophic, restrictive, myocarditis) or congenital heart disease other than bicuspid aortic valve.
3. Chronic kidney disease as defined as a pre-transplant GFR <80
4. Central line in both upper extremities.
5. Known peripheral vascular disease or vasculitis.
6. Platelet count less than 30,000.
7. Known clotting disorder or hypercoagulability
8. Non-English speaking patients.