For young plants chicken wire domes work well, but if you don't have access to chicken wire go to builders warehouse/mica or some hardware store....
1m by 3m shade netting 40% ( R40-R50 )density and 3 sticks bout 200-400cm in length. Make a tripod with the sticks above your plant and then cut out shade cloth to fit. Use cut out design to do the rest of your cut outs from shade netting.
It will stop cats, birds and this extreme heat we having from killing your girls at this young age. Growers up and down the country are crying right now outdoors cause our summer are only going to get hotter in years to come... Some guys are losing 10-100 young plants at a time up in nelspruit area I've seen/heard.