It’s not so much the Marmite but the clothing.
This week I was possibly the only bloke in Norfolk wearing a long sleeved shirt, long trousers and socks with my shoes @ 28C. No Europeans that I came across in East Africa wore shorts or short sleeved shirts during rain season.
That said, in the sixties I worked in Inverinan Forest, on wind blow. When we southerners complained about the insects, the old ganger told us: “Get a good sweat on and droon the boogers.”