Field.Kind (Word)

Returns the type of link for a Field object. Possible return values are wdFieldKindCold - A field that does not have a result, for example, an Index Entry (XE), Table of Contents Entry (TC), or Private field, wdFieldKindHot - A field that's automatically updated each time it is displayed or each time the page is reformatted, but which can also be manually updated (for example, INCLUDEPICTURE or FORMDROPDOWN), wdFieldKindNone - An invalid field (for example, a pair of field characters with nothing inside), wdFieldKindWarm - A field that can be updated and has a result. This type includes fields that are automatically updated when the source changes and fields that can be manually updated (for example, DATE or INCLUDETEXT).

For Each aField In ActiveDocument.Fields 
 If aField.Kind = wdFieldKindWarm Then aField.Update 
Next aField