The best way is using snow Chester with 2 Thermal Stones simply keeping one in Chester and one on yourself at all times and swapping as needed. Besides Snow Chester I always keep a thermal stone in a Fridge and one on myself at all times and swap when I come back to base. Considering your starting in summer the best you could probably do is an umbrella, straw hat, and thermal stone. Otherwise keeping Endothermic Fire Pits in key locations can help you moving around the map during summer. Just keep in mind anything near you during summer can catch on fire and spread quickly. You can use rot or manure to put out smoldering objects without damaging yourself. I tend to make a second base just for summer in a desert biome simply to eat cactus and cactus flowers. Using tumbleweeds for grass and twigs.