You should avoid all demonstrations and large gatherings anywhere in the country as they could quickly become violent. There were riots and protests in Lomé in August 2012 and also in April 2013. See Political situation
There’s no formal British diplomatic representation in Togo. In case of an emergency you should contact the British High Commission in Accra, Ghana. There’s an Honorary Consul in Togo, who can offer limited help.
There is a low threat from terrorism. See Terrorism
Take out comprehensive travel and medical insurance before you travel.