this definitely happens to me also. for many people, like myself, who take lithium, the summer heat and sunlight can be dreadful on intense days. this has caused me to stay indoors more - not the best for my mental health, but i get so agitated when i sweat ridiculously and constantly gripe about the heat. bring water with you wherever you go, make sure you're going to the bathroom often, and sunscreen is a must if you're sensitive to the sunlight. good luck.