It's struggling to get the equipment to protect its doctors, pilots and patients.
The air ambulance, which covers Oxfordshire, says it's taking steps to reduce the risk of infection, but it needs the help of local businesses.
It's calling on the likes of DIY stores, builders merchants and beauty salons to help boost its supplies, as it's struggling to get hold of personal protective equipment (PPE).
A spokesperson said its paramedics, doctors and pilots are regularly in close contact with patients, creating a risk of infection.
A statement on the Thames Valley Air Ambulance website added: "Despite the pandemic, our community still needs our hospital-level treatment for those who are suffering life-threatening illnesses and injuries.
"While our crew are not being called out to patients known to, or suspected to, have COVID-19 – our crew are regularly in close contact with patients, creating a risk of infection.
"It is vital that our crew are protected from COVID-19 so that they can continue delivering advanced medical care without spreading the virus."
The items required are:
- Disposable FFP3 Respirator Face Masks
- Fluid-resistant Type IIR Surgical Masks
- Coverall Suits Cat 3 Type 5/6
- Clinical Aprons
- Surgical Gloves
- Anti-fog Glasses
- Anti-bacterial Wipes/Gel Small and Large
The TVAA added: "We are currently struggling to guarantee supplies due to increased demand for these items during the pandemic.
"Independent emergency healthcare services, like Thames Valley Air Ambulance, are not currently part of the official distribution pathways for consumable equipment being used to protect NHS workers from the virus.
"While we are in constant contact, and coordinating closely with, local NHS services, we are trying not to add to the pressure of these official stocks if possible."
Anyone who is able to help boost the air ambulance stocks is urged to email email@example.com or call 0300 999 0135 and leave a message with details.