The four arms are: 1) combined intervention group receiving permethrin treated uniform (PTU) and 30% DEET (diethyl toluamide) liposome formula; 2) permethrin intervention group receiving PTU and placebo lotion; 3) DEET intervention group receiving untreated army combat uniform (ACU) and 30% DEET liposome formula; 4) placebo group receiving untreated ACU and placebo lotion. Both participants and investigators will be blinded to treatment allocation.