When the US military was segregated who tended to wounded Black soldiers on the battlefield? Would a White medic carry them away to safety?

I am excluding Air Corps units such as the Tuskegee Airmen in the context of this question, as in a proportional sense when compared to ground units such as infantry regiments, relatively few of the personnel of most Air Corps units were actually routinely engaged in "combat," and their initial echelons of care were provided by fixed units at their bases, like station hospitals.

The attached enlisted medical personnel and/or assigned medical battalions of the relatively few African American combat units (separate battalions or divisions) during World War II were all African Americans. These personnel were those who provided the first and second echelons of first aid on the battlefield; the soldier attempting to treat themselves or being attended to by attached medical personnel, and being taken to the divisional-level medical battalion or equivalent unit. Second-echelon care for segregated non-divisional units such as the several African American tank or field artillery battalions was provided by separate medical collecting and clearing companies, themselves assigned to separate medical battalions associated with the field armies; with only a small number of exceptions (see below), these units were manned by white personnel.

The medical officers of attached or assigned units associated with the African American ground combat units were initially all white, because there were at first few qualified African American medical officers, and it was a strict taboo within the Army about having African American officers command white troops.

There were a few African American-manned separate medical units formed, but they were dwarfed by the much larger number of white-manned units, however. Some of these African American medical units did eventually receive African American officers. The Medical Administrative Corps, intended to relieve qualified clinicians of paperwork duty so they could focus on their practice, counted 213 African American officers by the end of the war.

After the passage of the Selective Training and Service Act of 1940, the Army was required to find a place for the increasing number of African American soldiers it was receiving. African American enlisted men were also assigned to the Medical Department, although by the end of the war, the Medical Department was only 4.2% African American, compared with 10.3% in the Army as a whole (the latter figure basically matching the percentage of African Americans in the U.S. population). Few entirely African American (but, again, nearly without exception, with white officers) medical units were created, and they were mostly assigned to menial tasks instead of medical support. When the Medical Department established replacement training centers in 1941, they were given quotas to train limited numbers of African American enlisted men, who were housed and trained separately, in training units segregated from the white trainees.

The first attempt by the Medical Department in the early part of the war to find a place for African American soldiers other than by assignment to the existing African American units was the “medical sanitary company,” which was described initially as “a place to park Negroes: they had no set organization, equipment, or vehicles. As late as 1943, sanitary companies were formed when the AMEDD needed units to receive Negro draftees.” Later, one company was intended to be assigned to each general hospital, to provide messing facilities to the few African American doctors or nurses assigned thereto. Eighteen companies were deployed to Europe and eight to the Pacific, where they performed various tasks like manual labor support for other African American units such as those assigned to the Quartermaster Corps, malaria control and other sanitation work, and unloading hospital trains and ships.

In 1943, three ambulance battalions of African American soldiers, each with three ambulance companies, were formed. They were later broken up into separate medical battalion headquarters (which could have separate medical units such as collecting, clearing, or ambulance companies attached to them, and were themselves assigned to medical groups) with their subordinate companies becoming separate numbered ambulance companies. “The Army readily attached white units to these battalions, showing no discrimination in that regard, although since the battalions had white officers there was no question of putting Negroes in command of whites.”