If you would like to serve your community using your EMT certification in the future, why not just complete the certification process first? In the state where I live EMT training is a study intensive course equivalent to the workload of two college courses lasting a minimum of 190 hours. You can transfer your license to the state where you attend college. EMT is a commitment. I don't know where you can get a summer EMT volunteer/paid position. Most places require at least a year commitment. No one knows how long this pandemic will last. Places where high school volunteers can serve most likely have temporarily suspend all volunteer activities.

If you just want to check the box for some kind of apps, I'd not recommend doing it.