Dear reader, 
I understand your concern. Infact, during my college days, I too faced the problem of feeling low and tired during summers.This usually happens due to dehydration and a drop in BP. I always carried ORS with me during my clinical postings to manage this. However with every passing year, the summers are getting extreme causing us to bear the brunt of heatwaves. 
 I have collated some easy to follow tips for you to stay safe from  heat waves-

1. Avoid Going Out During Peak Hours – Prefer staying indoors between 11 am and 5 pm when the heat is most intense. You can tweak your travel time accordingly.
2. OOTW (Outfit Of The Wave) – Dress in light colours and loose-fitting clothes to stay cool.
   1. Use scarfs, umbrellas, and caps to limit direct sun exposure.
   2. Wear sunglasses to protect your eyes and the sensitive skin around them.
3.  Stay Hydrated-
   1. Drink plenty of fluids such as water, buttermilk/lassi, fruit juices, coconut water, lemonade, and ORS (Oral Rehydration Solution).
   2. Avoid hot tea/coffee, alcohol, and sugary sodas which can contribute to dehydration.
4. Eat Healthy:
   1.  Consume light meals, fruits with high water content, and foods high in fiber and protein.
   2. Avoid fried and spicy foods as well as stale or leftover food, which can be harder to digest in hot weather.
5. Apply Sunscreen- Use sunscreens with SPF 30 or above to protect your skin from tanning and sun damage.
6. Avoid Exertion- Do not overexert, hot weather can lead to heat exhaustion.
7. Monitor Blood Pressure and Blood Sugar- Check your blood pressure and blood sugar levels when you feel low. Consult a doctor if the readings are deranged or symptoms persist even after following these measures and maintaining hydration. 

Hope this helps.
Wish you good health.