Do not use a sunblock-insect repellent combination; apply them separately.

Since both sunblock and insect repellents come in a range of strengths and last for disparate periods of time, it is unclear how well either defense will work when combined in a single lotion or spray. Apply your sunblock first, then apply your insect repellent at least ten minutes later to preserve the effectiveness of both the sunblock and the insect repellent.